Should I switch my baby to the other breast?

Doesn't have to be. I feed due to having a lot of milk but only one breast per session. That's been the case for both kids already.

Breastfeeding is very personal and mostly comes down to your gut feeling. So definitely ask a maternity care nurse or a doctor who knows you. When my little one let go after the first breast (I'm not one for clock-watching, but after at least 10 minutes), I always offered the other one, and my son would drink from that too. Then I'd just keep offering the second breast, but if your baby falls asleep satisfied after just 3 sips from the second breast, then your baby doesn't need it.

I don't agree with that. A baby can also fall asleep because they're not getting enough milk and have no strength left. Always start with supplementing with formula! Your breasts are still producing in the first 3 days, and it's possible you're producing too little! Postpartum care often weighs them too little. Breastfeeding really gets going well only after 3 days! Then you'll also get engorgement, and you can stop the extra formula! But really offer something via formula during those first 3 days. And get a scale yourself and weigh every feed! My little one ended up in the hospital due to malnutrition and dehydration, and according to the postpartum care, everything was going super well because the baby was sleeping! Never again for me, but everyone's choice.

Sorry, but I don't think your advice is good for a smooth breastfeeding journey, Hummeltje! BF definitely needs to get going, but you achieve that by latching on as much and as often as possible! Your breasts need to adjust to the demand, and if you supplement with a bottle, they don't get that signal enough. Empty breasts are a sign that more milk needs to be made, not that a bottle should be given.
I do agree that a baby can sometimes be too tired to drink, which is why I got the advice early on to change the diaper after the first breast so she would wake up properly, and to tickle her feet or the book while she was drinking if she fell asleep. I also always offered the second breast after the first one, and sometimes she drank well from it, sometimes just a few more sips. Here she was a fast drinker though, so not exactly on the clock but mostly by feel.

I've been breastfeeding for 13.5 months now

Are you already breastfeeding Amy?

It really depends on your start. I had a C-section, so it took longer for my milk to come in. That’s why my baby got a little bit of formula via finger feeding a few times on the second day because he was restless. But then I also pumped quite regularly to kickstart production.

You definitely shouldn’t let the little one go hungry, no! Breastfeeding is great, but only if it works!

If you’re unsure, you can buy a book about breastfeeding. It has all kinds of tips on the signals your baby gives to show if they’ve had enough, whether they’re latching well, and also good positions and tips for any problems.

Having prior knowledge from books combined with a postpartum care worker with good training helped me enormously.

I only breastfed for 5 months because it became difficult with work, but I really enjoyed that time.

But to get back to your question, offer the second breast and start again with the last breast used next time so that it gets emptied.

The tip about changing a diaper can indeed help wake them up, or massaging the reflex points.

After a while, when they stay awake a bit longer, you should pay attention to their rhythm. Make sure they’re not too tired to feed. For us, the rhythm helped; feed, be awake, sleep, and then feed again.

Totally agree with Betty! Especially start with the breast she drank from last, so she gets the thicker, more nutritious milk!

You should definitely offer both breasts and latch on each time to help increase your supply! But what harm could it do to also offer a 10ml bottle just to be on the safe side? As someone else already pointed out, not everyone produces milk equally well right away. That's why I also recommend weighing your baby before each feed so you know how much they're actually getting. But if it's not much, you can still keep offering the breast—it still needs to be fed, so just keep bottles on hand.

Personally, I wouldn't weigh every feed. You can drive yourself crazy with that. But weighing once a day around the same time is definitely a good idea. That way you can also see if your little one is gaining weight. They drink more from one feed than the other. Also, formula is indeed very personal. As long as your little one is gaining weight daily, I wouldn't quickly add bottle feeds if you're breastfeeding. This is to stimulate breastfeeding. Always discuss this with your midwife. I myself got advice to first offer both breasts to get breastfeeding going well and to prevent my little one from losing too much weight, then give 20 cc of formula, and then immediately pump again to stimulate breastfeeding. After that, I could top up the pumped milk with formula up to 20 cc after the breasts. Then my little one started gaining weight well and breastfeeding was going well, so I could stop with that.

If you really want good advice, check out LLL. They also have a Facebook page. They know everything about breastfeeding and you'll get the right information there. I'm giving my first baby breast milk and I've joined their Facebook page. I've already gotten a lot of useful information. You can ask them all your questions.

Up to what age do you guys plan to breastfeed if everything goes well? Our little girl is getting teeth—is that a good time to stop? I certainly don’t want her to bite my nipple! It’s still super convenient and special, but I’d actually like to get my old boobs back once in a while! Or is it wrong to think that? I feel a bit guilty saying it out loud—does that resonate with anyone?

I stopped breastfeeding my oldest when he was 1.5 years old. He was actually only drinking in the mornings back then, but I was pregnant with number 2 and he just didn't want to anymore.
Now it's been almost 10 months with number 2 at the breast. I think we'll go for about a year or 1.5 years.
I want to breastfeed for at least a year because then you don't need formula anymore and your child can also have cow's milk.

But you decide what's best for you. All breastfeeding you give your child is good. If you want to switch to a bottle, that's totally fine!
I can tell you that biting the nipple is often just a short phase. Just pull the nipple away and they'll make the connection that biting means no more milk.