How often to pump if also breastfeeding?

course11

I've had problems with DS's latch since birth (he's 3 weeks now) and only in the last week or so have I been able to nurse him at all. Before that I was advised by two LC's to pump every 2-3 hours and we were feeding him whatever I expressed, and formula. It was hard to keep up with that schedule.

Now that I am home alone with DS, and now that he is BFing 4-5 times a day (still supplementing w/ formula), I neither know how often I should be pumping nor do I find it easy to actually make time to pump even with a handsfree pumping bra.

So am I screwing up my milk supply if I'm only getting in 2-3 pump sessions a day? I'm on Reglin and the most I've ever pumped in one session is 2.5oz out of one breast (I had a mastectomy so only have the one boob to work with). Usually I average 1.3-1.8 oz per session.