Feeling discouraged

My husband and I had unprotected sex for about 10 months (not trying, not preventing). During that time I lost 50 pounds. I am not sure if I ovulated some months, because of drastic weight changes from month to month. But I never got pregnant. We officially decided to start *trying* in November of 2015. We got pregnant on our first try but sadly lost the pregnancy at 5 weeks (might have been earlier, started spotting the day before I found out I was pregnant). We have been trying ever since to get pregnant again, and I'm still not. My cycles are usually 31-35 days apart, and I usually have heavy bleeding (multiple large clots) and cramping on the 2nd day of my period. I'd like to mention that we have a son together who was born in 2011. I'm worried about possible endometriosis. ANY insight is appreciated. TIA