1 day of period

Hey everyone,

I'm going to the doctor tomorrow (read: soon) or Monday to get my blood drawn. Lately I've been feeling a bit faint like most people do, but I didn't really think much of it. But now my 'period' (if it was a period, but I think it was because it would be a bit late for implantation bleeding if I can trust the internet) only lasted 1 day and started a day later than usual, whereas it normally lasts 4-5 days and is fairly regular since I'm on the pill, so I'm getting a bit worried..

I did switch medication (I take anti-anxiety meds, but I won't go into that now), so they say you can sometimes experience changes from that, but, I also started my pill a week late because it ran out and I couldn't get in touch with the doctor.. My boyfriend didn't cum inside, actually for that reason, but I'm aware that it's not 100% safe, though I still think it's a bit far-fetched to be pregnant..

I've had some sore breasts in the last week but it could be that I'm just imagining it. The rest of the symptoms like fatigue, heartburn, and a bloated belly (but I also get that when I'm about to get my period) are quite pronounced. Well, everyone's been pretty sick lately so I'm not sure what to make of it..

What do you guys think?