Had sex last Wednesday , the condom broke and right after the following day, Thursday, I bought a plan b pill at Walgreens , now it's been 10 days since the incident and 9 since I took the plan b pill. Should I be worried it's been 9 days and I still haven't had my period? My period is irregular so I don't know if I've missed it or if it's just late. Please help me! Should I be worried? And when should I go buy a pregnancy test? Thank you