What Causes Itchy Burning Sensation In Pelvic Region?

Hello, I am a 33 year old female with 2 children. Both Natural birth. I have started a intense aerobic workout that i've been doing for 3 months now. I have had ichy burning sensation for the past few month in the pelvic region. Internal pelvic area nothing external. I have found that when I do get to hot during my exercise routine, my pelvic region starts to itch and burn. If I let myself cool down, the itch and burn will go away. But later on i need use the restroom to find I have dierreah. Lately I have had some spotting after I urinate and my last menstral cycle was pretty painful. I'm used to heavy periods, but these last few years have been alot heavier. Also at times upper middle spine area and my lower back will feel like it itches, but the itch will feel as if it is in the bone. What could be some reasons for this?