Possible ectopic or miscarriage?

FINAL EDIT: I miscarried my sweet little baby.

EDIT: I went to the doctor yesterday, she couldn’t say for certain if what she found was a gestational sack of not. She told me I was at risk of miscarriage but set me up to get another scan done in 1week. Unfortunately I have been cramping all day, and my bleeding has changed from brown to bright red. I think I’m beginning to miscarry. Leaving my post up incase someone else ends up in the same situation and is needing possible answers.

I have had a worried feeling & just felt like I knew something wasn't right since getting a positive test on 6/21. (Thought I had heavy implantation spotting on 6/17-6/18). I have continued testing occasionally because my first test was extremely light for how far along I should have been. My tests have not changed hardly at all, and are still extremely light. I ended up getting an abdominal and vaginal US on 6/27. Based on my LMP (4/17) I should have been roughly 9w3d at my appointment on 6/27, but she could not find anything in my uterus. She told me that based on this I was either within my 4th week (potentially because of my long 38/39 day cycles?) or it could have been a chemical or is ectopic. Since that appointment I have had cramping ranging from very mild to occasionally severe, along with mild dark brown spotting (6/27-7/4).

I was told that if I waited 2-3 weeks from my 6/27 appointment then got another US that we would be able to see a yolk sac/heartbeat by then if there was one.