i am 17, me and my ex had, had sex it was my first time. we used a condom and he had cum in it. we had sex on march 13th 2013 and it is now march 18th 2013 i havent been feeling well. ive been sick to my stomach and getting head aches been very tried and been peeing alot also having hot flashes and cramps. could i be pregnant? when should i take a test?