2 positive preg test but neg one this moring?

i took 2 preg test one at 2 weeks after sex and one at 3 weeks and both had faint positive the one i took this morning was negative its was a walgreen brand and i hear they are bad ones but anyways im thinkin of going to a clinic and i cant find one that does a blood test in nyc so tell me what yall think am i preg? mine signs are breast tenderness nassua back pain and i feel perssure on my hips under my stomach where theres a bump