whats wrong with me?

hey ladies,

Well for the past few months i have kept thinking im pregnant but all the tests i have taken have been negative but i still feel pregnant. I hadnt had my period for a few months up until the 4th of this month (JULY) and finished on the 10th..The day before my period i had sex, but my period wasnt really like a period it was really light and got lighter and lighter then went..im always eating and wen im not eating im cranky or sleeping..could i be pregnant? plz help!! i dont want to go to the doctors to have a test if there is no point.
thankyou