Baby dance

Me and my hubby are ttc for baby # 2. It took 6 months to get pregnant the first time but we where not really trying and only having sex times a 2-4 week.  Now with a four year old me working days and him nights we are hardly in the mood. Can we still make a baby having sex 2-3 week. I'm trying to push him more when I'm ovulating but sometimes we are just so tired. Anyone else had this issue?