Irregular or..?

I really just need reassurance as I get bad anxiety thinking of these things. My bf & I never have sex because I’m constantly worried about the possibility of getting pregnant (I have super high anxiety) well we had protected sex about 3 weeks ago but stopped literally a minute in because I got nervous. He didn’t cum inside me, etc. my period is currently 20 days late, but this isn’t unusual for me?? Last month it was around 15 days? I have times where I am super regular and then other time when I’m so off. However, I feel so off this time? Any advice as to what I should do to relax or if I should seek help about my irregularity? Should I take a pregnancy test? I don’t think there is much possibility and the though of testing drives my nerves crazy!