Low hcg levels, no symptoms, no bleeding, no pain

I had a miscarriage in January and a CP in July. Then in August I received my bfp 10dpo. Then at 4w2d (16dpo) I got a blood test done, my hcg levels were 87. I felt it was low. I turned 5w last Saturday, I had some stabbing pains in my lower abdomen. I have also been having sore breasts and felt hungry. At 5w2d my symptoms had almost completely disappeared, the only one I keep having is a watery discharge all the time (my underwear gets wet), nothing else, not nausea not sore breasts no cramps. Yesterday At 5w5d I decided to get another blood test, results were 879. My levels haven’t been rising as they should (they’ve doubled maybe every 72 hours). Today Ive had some sharp pains (it feels like burning somewhat) in my lower abdomen, but only a few times. The watery discharge is still there. I don’t feel pregnant anymore. I’m almost convinced this won’t have a happy ending. I have an ultrasound tomorrow, I hope we can see something, meaning anything, good or bad. I’m scared it could be ectopic, If it’s bad I would like all of this to be over so I can start trying again (I’m that pessimistic).

Any of you have been through something like this? Thanks in advance for your comments.