Took five HPT and they were all positive went to the clinic and my test was negative..whats wrong? lol?

hello..im very confuse i took five Home Pregnancy Test but i was on my period but the reason why i took the test it was bcs it wasnt a normal period it was very lite and it was gone by the 3rd day. but i will just spott, i went to a clinic three days ago and i took a prego test and it was negative. but she was kind and took another but this time there was a very bright pink and a very very but very lite line. im very confuse but exited if am! but any help?