I have never heard that there is a difference between it being called a disease versus a syndrome. I understand that it can be referred to as either, but generally the syndrome because there can be so many different factors and you may have all of them or only a couple. It can vary from person to person - therefore the word syndrome is used.
Anyhow...I, too only have few symptoms and it took forever to get my diagnosis due to this. It doesn't show up in my bloodwork, I am on the thinner side, etc. I was never put on any meds as well. I think this is due to having so few symptoms. Not over sure.
I do have a son. He is 9. It took us a while to conceive him and it was all before my diagnosis. My diagnosis came about after trying to conceive a second child. We were approx. 5 years into trying to conceive before I was diagnosed. We did 6 rounds of clomid with no luck. I had several "missed pregnancies" during both times of trying to conceive.
I hope this may give you a ray of hope to know that you aren't the only one that was never on meds and two that you can conceive. While I never did conceive a second child I do at least have one and this board is proof with all the pregnancies you see that anything is possible!
I wish you the best of luck with your ttc journey.
Confused and worried.. 
