Lump behind cervix ??

I was supposed to get my period about 3-4 days ago. Normally, it's like this. It can be off for a few days and I'll be fine. However, this feeling is just weird. My cervix is normally low (like right there low), open and a bit firm right before my period. Over the past few days, however, it's been high and firm but open. (O_o) Today when I checked it, I noticed it felt the same, well perhaps a bit lower. But what worried me is behind it, near the back wall of my vagina (perhaps by the separation of my vagina and anus if that makes sense), there's a firm lump that feels about the size of a golf ball. It hurts to touch and the pain from touching it can be felt on the right side of my abdomen. I also have dull but noticeable pain on my right side by my abdomenal area when I'm not touching it or doing anything at all. I thought maybe it was cramps but this is for sure different. I am going to wait until this week is over to make sure it's not Mother Nature playing games and it's not just a fluke. But after this week, if it's the same, I'll give my doctor a call. I was just wondering if any of you ladies went through the same thing or something similar? [For the record, I am not pregnant.]