Negative on PT but 9weeks preggy?

Hi momma's does this happened to anyone before? My last mens was Apr. 13-15 (3days) regular po yung menstruation ko, up until now i haven't got my period, i tried taking PT po twice sa bahay it's negative, then last week i decided to get check by an OB, one of the nurse assist me to take another PT still negative but then Dra. says I'm 9weeks pregnant na base on my last menstruation, and ask me to take Transvaginal Ultrasound (waiting lang po ko sa allowance ko for that kase medjo pricey) I feel a little change on my body & I'm also taking Folic acid rn as per prescription. Is it normal po?Does it happened to anyone else? What precautions do I need to do? #firsttimemom #AskingAsAnewMom #Needadvice