Hi, guys. I need a serious help right now. Can anybody tell me what's going on? Here is the thing: my ovulation day was on 3rd so we had sex that day unprotected obviously. I don't have my period, it's already late 7 days. Two days ago I took pregnancy test it became negative. My last period was 20th of July. This month it sopouse to be on 18th. But still no period or positivity on pregnancy test. Should I be worried or simply my period is late? Can anyone tell me some advice?