Confused and Nervous

My husband and I just recently started trying for a third child. Period due next week so possibly could be pregnant. It's something I have been wanting to do so much for the past year but kept putting it off, fearing it was only baby fever and we were not ready to add to our family. Now that we have started trying, I am over whelmed with emotions. I feel regret and scared that we may have made a bad choice, yet I'm still yearning for one more child. I feel so confused on what I want. Waiting and thinking about whether I will get my period next week is leaving me stressed. Anyone else ever feel this way?