Help!

I've been ttc for a year, although it seems like forever. I had a miscarriage July 2014 one week after finding out I was 8wks pregnant. I've had baby fever since. I'm thinking of using preseed but unsure if my boyfriend of 2yrs will agree. He has 2 sons from a previous marriage but we both want a daughter. We haven't talked about having children since the miscarriage but I have severe baby fever. Not to mention I'm getting older and would like to have a baby now rather than later. Should I use preseed without him knowing?