I'm kinda worried now...

My boyfriend and I mutually masturbate about once a week and just recently he has been a bit curious n been putting his fingers into my vagina...

This happened for the first time mid of last month... and for the whole of last month, I didn't get my period... which I only realized this month (and I still haven't got my period)... for a whole 2 weeks last week, I had an increase in vaginal discharge and a week before that, I got a sudden nauseous spell which lasted for about 3 days till I finally puked and all was well.

I'm worried that his fingers could have been contaminated with his semen or something (well, so is he)... though there are no other signs of pregnancy besides my period not appearing ._. I have yet to take a pregnancy test... but i really want to rule pregnancy out and this all just a result of stress... I started working in mid January and my office is not exactly the most friendly place in the world and since I'm just temporary staff, they've moved my workspace, every time, it gets smaller... I felt isolated and perhaps a bit stressed without myself really realizing it... So could it be that my period is late due to stress?

Please help... I would like some good advice before I go to a doctor of take a pregnancy test... and sorry for the long windy post >w<