need advice for a friend....low hcg numbers (pg...m/c ment...)

Hey Ladies, could use some insight for my friend if you don't mind. She said she's currently around 6 weeks "Pregnant" but having suuuper low hcg levels. She had unprotected sex on May 6th.

First hcg level about 2 weeks after her unprotected sex was 12...2 days later, 13, 2 more days later 19...then 4 days later, 42, now her latest draw 3 days later is 71.

She's having tons of anxiety b/c of the unknown. She's okay with this pregnancy going either way...miscarriage or not. But she's pretty desperate for some ideas on what could be going on. Unfortunately, I know it's a waiting game at this point. But I don't see how there's any way HCG levels this low could result in a healthy pregnancy right??? Could it be ectopic??? She had AF like bleeding at first, but nothing now. Does she have to be bleeding in order for her hcg numbers to be decreasing???

Any advice is appreciated. Good or bad outcomes welcome.

Amy