TTC for 6 months

I get so excited that I'm going to miss my period and I don't.. This is really becoming so stressful for me that I told my partner I give up totally! I have a son already who will be 10 in a couple of days and he wants a sibling just as much as I want him to have one. I have dreams about a baby girl and she just smiles and stares at me the whole time. I just wonder if I should steer away from the whole idea of getting pregnant because it's causing to much disappointment and stress in my life