BF issues or is this normal?

oohgrrl11

I had DD on Friday via RCS. I put her to breast within 1 hour of birth. She immediately knew what do, unlike DS, who I had a hard time BFing and ended up EPing for a whole year, while supplementing due to low supply. I have large somewhat-flat nipples. DD was 9 lbs 13 oz and born with low blood sugar, 27, so the nurses gave her a little formula right away. She lost 10% of her body weight in the first 3 days so the LC, nurses and Ped agreed I should put her to breast and then offer 1 oz formula each feeding. I fed her every 2 hours after that. Yesterday my breasts felt heavier and tender and I was able to self-express a little milk and DD seemed content. I could hear her swallowing, and quit supplementing. Today I BF her and then we took a 2 hour nap. When we woke up I tried to BF her but it seemed like she wasn't getting anything. I tried to self-express- nothing. My nipples are sore and bleeding a bit. I then gave her some formula. Is it possible that my milk came and went? Is there anything I can do to get it to come back? I do have a pump but was hoping not to use it much in the beginning until we had a good latch and routine. Thanks.