hi, my boyfriend and i were rubbing up against each other. I was wearing cotton panties, cotton running shorts and he was wearing cotton boxers and cotton long pants. i sat on his lap and we were grinding and he came, this all happened 25 december 2012. i recently (2 months ago almost 3 months ago) changed pill from jaz to qlaira and last month my periods were very strange and they cam half way through the pack of pills... this month they have skipped and im feeling bloated and wierd. i dont recal having sperm on my vagina opening as we were both clothed and i was only rubbing for clitoral stimulation. i did see 2 wet patches on my shorts over my mound area. i am worried though because im skipping periods... I can be pregnant now, i can not afford a kid at this stage. please help... what are the chances of pregnancy in my situation?