Positive Pregnancy Test But Low HCG.. Help

February 3rd I used Ovidrel injection and 15 days post injection I got my first positive pregnancy test so I called and had my first HCG blood draw Feb 20th and it came back as 30.6 & Progesterone was 16.06 they told me to come back and let’s see if it doubles like it should, so Feb 23 I went back and it was only 48.6 & Progesterone was 13.85 they said that HCG did not double like they had hoped But they want me to come back again Monday the 27th just to see if it has climbed… Nurse practitioner said that if it doesn’t then the pregnancy is not a viable pregnancy…. I was sooo happy yesterday before I got my second blood results back and now I just feel like my joy has been snatched away so quickly I just don’t even care to leave the house now.. Deep down I’m hoping that it was just early and maybe the numbers will rise but I know she did not sound too confident. I’am currently 21 days Post Injection. I’ve never had a non-viable pregnancy nor a miscarriage, and I have so many questions,

Could it just be early still for the levels to rise? Ive had one successful pregnancy and they doubled normally.

What type of pregnancy could it be for it to be a loss this early? (I’m scared of a tubal rupture but no ultrasound has been done yet to see location)

How soon is the miscarriage process over?

Will it hurt to the point of being unbearable if I’m out in public when it happens?

Will it be just like a period?

There’s so many things running through my mind. It hurts to even think about it anymore but it’s the only thing on my mind….