Issue with my menstrual cycle. Pregnant?

I'm dealing with PCOS and depression so I'm having second thoughts...because I had sex in feb protection didn't work I took pill with in 24hrs then March I was on my periods for four days... After that I'm missing my periods... Is there any chance that I'm pregnant? I didn't see any symptoms of it and as I'm home with my family couldn't check it... I jus wanted to know that is that possible having periods the next month after having sex and then stops... I'm confused because I have PCOS too that reduces my fertility power... As I'm very fit n it's in control that's why I'm having this confusion... Depression may have caused it also I'm depressed since 9 months but never missed periods more than one month. This time it's been two months and seems like this month also it wouldn't come. Please help me out!!