okay so i had intercourse with my boyfriend about two weeks ago i was late on my period for about 3 days and today at school i started bleeding and it was a lot and it was dark red and i have cramps too and well now on my pad is a light red and not a lot comes out but when i wipe its a dark red and its a good amount of blood can i be pregnant should i take a pregnancy test and is this a sign of my menstrual period and does sometimes does this happen the first day of mestrual period please right back asap im nervous!!!!!