Fluctuating HCG levels success stories?

Hey all! So I'm very concerned... I found out about a week ago that I was finally pregnant. I've been TTC for around 17 months and been on fertility treatments the last 7 months. This is my first pregnancy so as you can imagine mine and my husbands excitement upon finding out the news. Anyway, I got my beta test done and my hcg level came back at 48 at 4 weeks. 2 days later, I got another beta done and it dropped 4 points.. 44. The next day at my doctor appointment, I was told it was a bio-chemical pregnancy and they were about to give me the rohgam shot that same day but luckily it was unavailable at the time at my local pharmacy. So they decided to do another blood test that day just to be sure. The 3rd beta rose to 55. Doctor said it still didn't look good but that I should continue my progesterone suppositories. I have another beta tomorrow (at 5 weeks) and I'm so scared to find out the results. I had cramps a couple times this past week but they weren't one-sided and they didn't last long. I have no bleeding... Is there anyone out there that had fluctuating hcg numbers in early pregnancy and went on to have a healthy baby?? I've been scouring the internet but I can't find anyone who had numbers like mine. I need some hope...