Wow good to know it isn't only me that feels this way - I do feel for you, it must have been awful
I would suggest if you feel something isn't right get checked; mention it, and do it as soon as possible; we all are known for putting it off, there's no time like the present. If you've been on the pill for heavy and painful periods it will stall endo or any other hormone dependent problems for a while. Other things to consider are fibroids and polycystic ovaries (PCOS). Endo is as common as diabetes in women - 1 in 10. Unfortunately it's diagnosed later in life when women realise they have problems conceiving, intense pain and irregular bleeds (inbetween periods) or heavy bleeding (mine was pads and tampons often for 7 days or more about three times a month)
Definitely worth keeping a diary of pains, bear in mind this can include at any time of the month:
abdominal pain (if endo is sticking organs together)
frequent urination (if endo is on the bladder)
digestive problems (if endo is on the colon)
bleeding and spotting that is not normal
tired or feeling exhausted
recurrent infections (colds, uti, upset stomach)]
The only way for a confirmed diagnosis is laparoscopy, which I suggest going for - it is still an operation but if it helps to see what's wrong then it's a step forward it can also be used to do a health check of reproductive organs. If you have insurance to be referred privately or pay on your own go for it - they will take the extra step and remove what they can if they see any in one operation. That's what I went for. Also less waiting time; I went from consultation to op in less than a month.
Fibroids and PCOS they can do an ultrasounds both the normal stomach one and an internal (scanner up the vagina); it feels like a smear test.
Bear in mind if it is that, it is a disease, it will either stay the same, or get worse, and there is no cure, treatment (surgery / hormones) and getting to know your body is best. But we endo sisters can help each other