BD during fertile week

I am feeling kind of bad because my husband and I seem to only BD during my fertile week. He has a very low drive and I have just gotten used to it, but I make sure we BD when it counts! Does anyone else notice they BD so much more during their fertile week? I feel bad, like that is the only reason we BD, but its just not worth the aggravation of trying to get him interested any other time of the month...