I found a bigger lump in my last night?

My fiance' and I were messin' around last night and he touched my an it felt a little sore so I touched it and I felt a bigger lump than before, now a year or so ago I felt some lumps in my and I went to get a mamogram and they told me that they were cyst and not to be concerned but last night I felt one that was bigger than before do you think it still maybe cyst? or should I be really worried. Please help!!