Anyone get pregnant on bc pills

If you got pregnant on bc pills how did you know?
I plan on testing this weekend, but I’m extremely worried as I was obviously on birth control to prevent a baby. We have a 2 year old and 1 year old.
I’m on my fourth month of pills after trying the mirena and nuva ring and not liking them. the first 2 months I was on one that caused my periods to come on the wrong week, I switched to a different one last month and I bled one day lightly a couple days before the last week, and didn’t bleed at all on the period week. I have a few symptoms that are hinting at possible pregnancy but really hoping it’s not. anyone else have had this issue and turn out to not be?