Hcg levels are the devil - not increasing enough

MB

I had bloods done recently to check hcg levels after some slight cramping. At 5 weeks 1 day they were at 5500 (fine), but 2 days later they’d only gone up to 7200. The nurse has tried not to worry me but I have to go back after the weekend - not sure whether they’ll do more bloods or an US or what. Just wondering if anyone has had a similar experience that has ended well? I’m in anxiety hell, googling all the things! Some success stories or reassurance would be much appreciated! Thank you :)