strange things are happening

Okay so I've just gotten up (had an active day) and I was in a searing amount of pain. It can be best described as near my ovaries on the left hand side. My immediate reaction was to press quite firmly and guess what it made it worse. I then come to feel that there is a considerable lump but no bruising or irritation on the skin. It is very very tender around that area and I hadn't noticed until now. Is this cause for conecern or not? I'm going to the doctors tomorrow to pick up a letter but is it worth mentioning it? Thanks for any help and any comments I'm just worried and nervous and in pain!