i had protected sex on june 11 then about a week later had a really light not much blood kind of period then had protected sex again july 13. Then on thursday july 19 i took a pregnancy test it said not pregnant. But still no period then a week later thursday 26 took one more and still said not pregnant but i haven't had my period and its 10 days late. Am i pregnant if not whats wrong with me????

please help ASAP