Hard lumps in stomach

Im around 12 weeks pregnant (haven't had a scan yet due to covid-19. Having one in 3 weeks and haven't had a period in 5 months)

When I lie flat on my back I can feel 2 very solid bumps a bit bigger than a golfball. Could that be twins? Or could I have cysts?? They definitely went there a few weeks ago. (I'm very slim, I do however have a bump now which is another reason I though it could be twins, 3rd baby)

I keep getting cramps too, worse than I did with my other two but that's quite normal so I'm not too concerned. But they are quite sore.

Should I contact the pregnancy unit and tell them or just wait the 3 weeks until my scan