Confused and some what emotional.

Here lately (like the past couple of days) I have been emotional and even the tiniest little thing. My husband and I have been TTC for a year now as of tomorrow (Oct 3rd.) While at work yesterday I was fine for the most part, but today I've felt like a total and complete train wreck I am crying for no reason or not knowing the reason why I feel the way I do. I was talking with one of my co-workers and she made that suggestion that I might be pregnant. I told I just started my period Sunday. She said she was like that when she was pregnant, getting upset about nothing. So I don't know what to do, or what to think. I guess I just need to vent a little and maybe get some advice from others in my situation.