Why can't I get pregnant??

Me and my boyfriend have been TTC for 2 years now. Almost 2 weeks ago I took a clear blue plus test and got a faint positive at the 3 minute mark, but I just took 3 HCG strip test this morning and one had a vvvvfl and the other 2 had nothing. Tips, answers, advice, anything would be appreciated please!
(I hope this is aloud in this group!)