Getting less than 1oz when pumping?!!

Melissa

My baby is 1 week old and I have been breastfeeding since he was born, with some pointers by a lactation specialiSt. I think he’s doing ok based on his seedy stools and he seems to go into a milk coma once he’s done but I wanted to test out my pump to stash up some milk for my husband. In both times I tried (once an hour after I nursed, once like 3 hours after I nursed), I got like 1/2 ounce, or like 7 mL. It doesnt even reach the first line on the measurements. I think the 24mm flange may be slightly too big so I ordered the 21mm and waiting for that time come in. But I’m wondering what’s going on here? My breasts feel a little sore for a day now, almost like lumpy firm and how they feel before a period (is that engorgement?). So I think my milk has come in? I’m not leaking at all though. I’ll go back to doctor on Friday to check baby’s weight gain so hopefully he’s on track, but why can’t I pump like ANY milk? And this concerns me that maybe he actually isn’t getting much milk from me at all?!!! Please help! All advice welcome!!! Again, I’m 7 days postpartum.