I had a similar experience, having a recall after my last mammogram. I know it's frightening and it seems like a long time to wait, but first of all, four out of five women will be fine. In my case, something was found but dealt with very quickly. I had another mammogram at the recall and, because it was confimed that something was found, a biopsy that found a cancerous lump. Following a lumpectomy and radiotherapy, I was given medication to take and I have a checkup every year. Just had my first and all was fine. 
I can't tell you not to worry. It's impossible for you not to do so, under the circumstances. All I can say is that the odds are on your side and, even if something is found, there's treatment available. Good luck and let us know how you get on. If you want to ask anything more, please do.Gill xx