I had unprotected sex on the 16th of May and its the 31st and still no period. I took plan b about a hour after sex and he didn't cum inside me, but I heard about pre cum, so I took plan b just to be safe. My period is also irregular, sometimes I could go a whole month and still not get my period. Do you think I'm pregnant? I also just got the depo provera shot about 2 weeks after the incident.