when to test?

Hi everyone,

I'm new here on this site but have already found a lot of support in all the posts I've read.

I stopped the pill in early September and am now on my 3rd cycle.
My 1st cycle lasted 36 days.
My 2nd cycle lasted 35 days.

I'm now on day 22 of my 3rd cycle. On day 14, I had some spotting when wiping, very little, just for one day. After doing some research, I came across the term "ovulation bleeding," although it seemed too early to me given that I had such long cycles the previous two months... Could it still have been ovulation bleeding?

Now, on day 22, I'm experiencing some symptoms that I hope are signs of pregnancy...
Headache - lower back pain - a lot of white discharge (I feel my underwear getting wet while walking, sorry for the details), a hollow feeling in my stomach as if I'm constantly hungry, and slight side twinges.

Could I be pregnant, based on my cycles being so long over the past two months... Could conception have already taken place?

When would be the best time to take a test? Should I wait until day 35 has passed?

Thanks in advance for your advice!
Kind regards,
Stefanie