Is Healthy Pregnancy Possible In Women Having Slow Increase In HCG Levels?

hi I have a 28-34 days period cycles, my last period was 2 Feb. I use a pregnancy test at home and it was + in 1 March. 2 march went to doctor beta was 155 nothing seen in vaginal ultrasound , 5 march repeated beta was 166 nothing seen in vaginal ultrasound. it has any possibility for healthy pregnancy? thanks