Please help me understand what happening...

I've been married for a short time but me and my partner are desprate to start our family. When I was first married and moved in with him I had a cycle and then missed three. Last month I had a cycle so we tried to conceive and now I have missed my period again. However I took a test this morning a it said negative. I don't know what to think now. I know it's only been a few months that we've been seriously trying so I know not to expect to become pregnant so soon. I just turned 20 in January and I feel sure I'm in peak condition to have a baby. If it's not pregnancy what is wrong? I think maybe stress but I couldn't say for sure. Btw before I was married I always had a consistent cycle and I have a slight appreciation towards hospitals, but I am willing to go if nessicary, but i also have some pretty serious angsity so I can't tell if I'm just blowing this out of proportion. Please help me, understand what's going on.