I had a abdominal ultrasound to see if I am pregnant, they said no fetus, but hpt positives at home?

Probably early preg. The scenario you speak of is common. Most commonly the pregnancy test is positive, but early such that it is not seen by an abdominal ultrasound. The vaginal probe ultrasound is more sensitive and can see a pregnancy earlier. Also, it is possible that you have a pregnancy which is either ectopic (not in the uterus) or not developing normally. Check 2 quantitative pregnancy tests 48 hours apart.