1 successful preg, one m/c, and one chemical preg

So I have a 21 month old and I had a m/c in Oct and to our surprise we found out on Sunday we were preg again. However, turns out it was a chemical preg and I started my period Thursday. I had no problem conceiving the first time. On the second try we were preg with our son. Now I'm wondering will I ever have more children. I have no idea why any of this is happening and I don't know what to do. Anyone gone through anything similar? Advice?