Whats the deal with false positives?!?

I took about 8 pregnancy tests they were early testing ones, they all came back positive. I didnt miss my period but my right breast is killing me. My doctor drew my blood(no results yet) and the urine test came back negative at his office and he said there was fertilization but no implantation aka false positive. I took another test now and it says positive again! So has this happened to anyone?