4 times got negative + got period , can still get pregnant?
I had have sex at Feb 20 2009. After one week , I feel heartburn.But I got my period at Mar 18 2009. But a little lighter than normal. And I took pregnancy test kit at Apr 2nd 2009 at night 11 pm. It gave me negative. And then I took another test kit at Apr 6 2009 at morning 11 am it also give me negative. After that I got period at Apr 10.This period look like normal period. And then I took pregnancy test again at Apr 22 (when I wake up early morning), also got negative. Took test again at Apr 28(morning first urine) , also got negative. But I still feeling heartburn. And my lower belly is very hard now. So I confuse now. Can I still be pregnant?