Heavy Heart and Broken Mindset

I need help here everyone, but let me set the tone for what I'm dealing with. I am already a mother of a hyper active 2 year old boy, and currently under the supervision of my doctor for pre-cancerous cells in my cervix. I've been dealing with this for about 4 months. I have also been with a man I was hoping to marry for the last almost year. I know someday he would like to marry me and drops hints all the time, and trust me; they are extremely obvious hints and we talk about it all the time. We made the decision TOGETHER to go off birth control. I am currently 2 days away from what is supposed to be my period. So far I have no signs of it coming. I have been wanting to have a baby for a long time. However, now that this may be happening for us I have noticed some EXTREME changes in his attitude and personality... This is really stressing me out and I don't know if I can take it.... I love him, I really do. And better yet my son loves him just as much. Am I being unreasonable seeing this or is it normal?? I'm just getting to my witts end...