im scared...i think im pregnant...im only 16

ok...im 16 and ive had my period since i was 12.it has never been regular.about a month ago...it was the a day after i had my period,but i had in a tampon just in case...that night somebody i trusted tried to have sex with me and i think that he ejaculated and i was straddling him and the only reason why he didnt enter me was because i had in that tampon. for the past week ive been tired and sick to my stomach. and my nipples are turning like a darker color and i have some bad headaches and my lower back has been kinda achy along with my stomach and my ovaries.not including how irratable ive been.and not to be so graphic but ive had like this clear runny snot-like discharge that ive never had before...

i think i may be overreacting but could i be pregnant??

opinions?

Whenever a penis was anywhere around your vagina area,there is a possiibility that you could be pregnant. WHen you said he ejaculated?did he ejaculated around your vagina area or the ejaculates could possibly got anywhere near your vagina?
I would say wait for your period to come and pregnancy signs don't really show until you are pregnant for around two or three months,but everyone is different. If you period is late for more than two weeks,I would suggest a home pregnancy test.

Is Anyone On This That Can Give Advice ?