Worried about cysts?

I'm new and sorry if this sounds self indulgent, I apologies to you all who have real concerns, however I had a mammogram two weeks ago and had to go back and have two cysts drained.  They redid the mammogram and I had an ultrasound, I was told everything was ok  however now I'm worried because I have received a letter which says they don't have enough information and I have to go back, but in 6 weeks so I thought if it was anything bad they would call me sooner however I can't help but worry as i had a cyst drained years ago and there was no follow up.  Has anyone had anything simular please or any suggestion whybi have to go bk