So confused

Sierra. • Pcos, ttc for 2 years , starting metformin.
So I have has pcos for 4 years. For the past 2 I have been ttc. A week ago I got a positive test for the first time ever. Then a few days later I got two negitives, my doctor says to test again this tues... I still have mild cramping and nausea  but I'm afraid I'm just gonna get a negitive again..