Give them a call just in case
If you are concerned I would ask for another blood test. Your hcg level should double every 48 hrs. About 3-4 months ago I found out I had an ectopic pregnancy as my hcg levels weren't high and weren't doubling every 48 hrs. I had to have emergency surgery and my right Fallopian tube had to be removed. My second cycle after my surgery I fell pregnant naturally with my left tube and when I had my first blood test they were high and did double in 48hrs. I'm now 7 1/2 weeks pregnant and know it doesn't hurt to ask for more blood tests. It's better to be on top of things and know what's going on rather that stress.
Hope that helps :)
I don't see the need to call.