lack of sex

i'm more sexual than my husband and would like sex more at least once a week. he would b ok with twice a month. he is home 3-5 days a week. he has erectile dysfunction so it isnt easy to do it. he takes viagra he is 37. i miss havn a normal sex life but i dont think it will improve much. i am 5 months pregnant but he was like this before.  he says he happy with our sex life. i bought stuff to spice it up but he dont seem too interested. guess what i am sayin is will things improve?