Chemical Pregnancy

Chasity
Hi ladies!! Me and hubby have been trying to conceive baby #2 for almost 10 months now. I got prego with my son at 18 and he is now a healthy 4 year old handful. :) Since I got pregnant with him very unexpectedly I thought baby #2 would be a piece of cake. Boy was I wrong!! I was a few days late for AF in December so we took 4 tests. Each one was a day a part. All were positive. But when I went to the doctor to get it verified the nurse said it was most likely a chemical pregnancy. Has anyone else had this happen to them? What do they mean? I just worry it may happen again.