Pregnancy usg report explanation. Help.

Hi,I had sex on March 19 and got my period at time(21 March). After that I miss my period for almost 5 months.. I did urine pregnancy test several times.. Sometimes it was clear negative,but sometimes it had two lines,one was dark and other one was very faint. I did usg on July..My usg report says, Uterus is normal in size, shape and position.Anteverted.Endometrial thickness (10 mm). No focal SOL is seen. Uterus measures = 84.4×30.7×51.0 mm Both ovaries are enlarged in volumes with multiple premature follicles at periphery-features of PCOD Rt. ovary measures=43.8×20.3×46.5 mm & volume 21.6 cc Lt. ovary measures=39.9×28.2×37.6 mm & volume 22.2 cc P.O.D=clear Impression=feature of PCOD My only question is if I am pregnant or not.. Can usg report be negative after 4 months of sex! Please help..