Hcg trends, anyone similar?

At exactly 4 weeks my hcg was 79, at 72 hours it had increased to 263, 48 hours later it increased to 477. It doubled nicely the first time, but from my second to third check it didn’t double in 48 hours. Anyone have a similar experience and everything turn out okay? I’ve had cramping since my missed period last week, no bleeding. I have a history of an ectopic pregnancy last year, so I’m so paranoid. I have an US on Monday to confirm where this pregnancy is, but my anxiety is through the roof waiting. It just doesn’t seem like a good thing that my third hcg didn’t double in 48 hours 😞. I hate all the waiting.