Am I nursing enough?

[BCsMom]

DS is just about to be 5months. About two weeks ago, he started sleeping through the night relatively regularly - he only wakes up once on other nights. I work FT, so I'm nursing him in the morning before he goes to daycare, then he's currently getting 4 bottles for 18 ounces total at daycare, and I nurse him before bed. I pump three times at work and added a regular pump session at night. So I'm pumping or nursing only 6-7 times per day, depending on whether he wakes up at night.

Today, a Saturday, he only nursed 5 times. I'll pump before bed, but then that's it. Should I be trying to nurse him more often? I know the 18 ounces at daycare is a lot (he's there about 10 hours), but since he's eating less at night I thought it would be okay. He has very short nursing sessions - often only 5-6 minutes. Thoughts? I'm just so worried about losing milk supply!