I am 8 days late for my period, and when I tested, I saw two lines, one dark and one light. I had an ultrasound, and the doctor said my endometrium is thick but no gestational sac was visible, possibly because the embryo is still implanting. So, I would like to ask if being late for my period, having a thick endometrium, and not seeing the gestational sac means I am pregnant?

I took a pregnancy test early in the morning for three consecutive days, and each time, the result showed one dark line and one faint line. Could you please let me know if this indicates pregnancy? Recently, I’ve been experiencing mild lower abdominal pain. I had a C-section 8 years ago and have a daughter.