Worried

I found out a week ago I was pregnant after ttc for 1 year. My ob wanted to see me early bc of my high risk pregnancy with my first son. They did an ultrasound and told me they see uterus thickening and corpus cyst and sent me for blood work on Friday got my results yesterday and my hcg was 105 another ultrasound and nothing was detected she sent me for more blood work and another appt this Thursday! I told her my cycles as she knows are not 28 days! I don’t get why they go by the last mensural. I probably ovulated CD 17-20 which would be the last week of February! I am worrying so much and hoping everything is okay. She hasn’t ruled out etopic pregnancy yet and I have to go every 3 days (2x) a week. Has anyone had hcg level at 105? I believe I’m early 4 weeks but I’m not sure...