Advice Please

So my period last 3 and a half days and normally its 4 to 5 days. My boyfriend and I had a passionate weekend before i started my period and when i had my period we had sex during and the next day its just stopped and spotted a little but there was no brown stuff that normally occurs after. So today i had coffee and peanut butter for breakfast. i started eating the peanut butter(which i love) and it tasted disgusting so i didnt eat anymore. i got to work and got myself a strawberry and chocolate Kind bar and i was eating that and with every bite i just wanted to vomit so i didnt finish it. Later on i got a chicken cobb salad for lunch and started eating that and started to get nausted and wanted to vomit, so i Threw it out. and ever since this morning ive constantly felt nausted and drained but i dont feel like i have the flu or anything. im thinking i am pregnant. what do you guys think?!?!?