Could I be pregnant?

I have extreme pregnancy phobia so I'm very scared right now. I practiced safe sex, condom plus pullout. The condom didn't break either so pre ejacule is unlikely. Now my period is sort of late for three days now. I have had breast soreness that I always have before my period, even some light cramps. I have mild brown spotting and sometimes red when I wipe. But that's not what I have ever experienced before. I usually get a strong flow and pain that has to be treated with pain killers. I've had a UTI and a yeast infection triggered by the strong antibiotics I took for the UTI just a while ago. I've also been under a lot of stress but I've been in similar circumstances before and never had this type of period or whatever it is. I still haven't taken a pregnancy test which I will do soon when I buy it. But I don't understand how I could be pregnant yet I'm still so paranoid and I would very much harm myself if I found out I was pregnant.