Positive then negatives

So I did 3 pregnancy test on Wednesday when I was 7dpo (I know way to early to be testing) but I got 3 positive tests (vvvfl) but since then all I've had are negatives. I'm now 10dpo and so far not got another positive. I feel nauseas, got painful nipples, I'm also getting a lot of discharge and I keep feeling really light headed. Kind of giving up hope now and expecting AF to come on Wednesday has anyone had this happen but still got their bfp