Married, Pregnant, just too tired for sex right now

by Aimee
(Arizona)

I have only been married a little over 2 years and already we are in a slump. We have a 2 yr old and a baby on the way, I am 7 months pregnant right now. After working all day and taking care of our toddler at night, for me there is no time for sex. I can't even put together the energy for a quickie, which my husband is practically begging me for at this point. I feel so guilty for making my husband wait for the right time, but I also don't want to feel obligated or pressured to do it. It has been 2 1/2 weeks, normally we have sex once a week or once every 2. The bottom line is that our sex drives are just not the same. Should I be giving my husband more, and I being selfish?