Period is late and I’ve been feeling so sick lately

My period is four days late 😓 and i have been so terribly nauseous lately. I am not on birth control as every type I have tried has made me incredibly ill. My boyfriend and I use condoms occasionally and I test for my ovulation. I take my temp and I use those ovulation strips. We usually use condoms on the days I’m ovulating but we just didn’t have sex at all this time during my fertile period. The last time I had sex was six days before the day I ovulated. I guess there’s still a possibility though so I’ll have to grab a pregnancy test when I go grocery shopping later. I’m very nervous. I would be happy to keep a baby if I’m pregnant, but I’d rather wait a few years if possible. Wish me luck!