Maybe this is a stupid question but.....

Keisha • ttc #2 for 9 mos, have a 7 year old daughter. Ready for my next little pumpkin!
How many times during your fertile period should you bd? Hubby and I both work full time jobs, not to mention being parents, it's kind of hard to find the time to bd. We bd once a day during my fertile period, and sometimes we don't do it at all. Can someone give me some advice?