Pregnancy scare

I have been having crazy periods, they are around 2-3 weeks apart and very painful I have had a doctors appointment Set up this Friday. But I had sex 8 days before my last period according to my app not in my fertile window. And well my period came...  But it's been 3.5 weeks and no period. We used protection and he pulled out. We always check the condom for holes. Is my period just acting up again or could I really be pregnant. This Friday is my doctors appoint though. Also not that my periods used to be 4 weeks apart, up until 3 months ago.