Negative test 5 dys early. still pregnant & pre-seed Question,?

So my husband and I our TTC#2 and We BD March 6,8, and i ovulated March 10. Well I am suppost to start my Period MArch 22 (monday). So i took a PT Mar17 and it was NEGAtive. I took the first response 5 dys early. My ? is is it still possible i am pregnant i feel cramping today, peeing a lot, always eating and i have been craving hot stuff a lot and mexican food. . I really hope i am this is our 2nd month trying after marina IUD removed Jan 29 2010. If not this month i got pre-seed also for next any stories about that working?