20 weeks and 3 days pregnant and the baby has just starting moving a tiny bit but its painful?

Hey, i'm 20 weeks and 3 days pregnant and i have just started feeling movement which i'm very happy and excited about. They are only faint movements but they are definitely there. Anyway it may be a silly question but i want to make sure. When the baby moves or kicks or whatever you wish to call it i get quite abit of sharp pain wherever it is that it kicks. I have tried ringing my surgery just to make sure the pain is normal but they are very busy and the phones go straight onto some recording about swine flu. Its probably nothing to worry about but i was just making sure? Is it really worth hling my midwife for this? Thanks.