Should a breast pump hurt inverted nipples?

[metsa]

I have inverted nipples. After I tried hand expressing colostrum and finding I was getting less and less each time, I decided to switch to formula. Then my milk came in, and I decided to see if I could express. I bought a cheap manual breast pump from Amazon, and the first time I tried it I was surprised to find that I was able to express a good amount of milk. Since then, I have got less and less milk each time, and now I get nothing with the pump. I do, however, get sore nipples. My nipples hurt when I try to pump, then they stay tender and hurt with anything touching them afterwards. Is this likely to be anything to do with the cheap pump, is it normal when starting to express, or is it the inverted nipples hurting when they're un-inverted? I understand that you have to keep trying to express to build up supply, but I don't want to keep going if I'm doing something wrong, or if it's just going to keep hurting.

I also had inverted nipples, and I found it hurt quite a bit. Partly I think due to the pump "stretching" the nipple outwards, and partly as I was using too high a setting and my nipples were getting cracked and blistered. I wrongly thought the higher the suction the more you'd get out, but it doesn't work like that, so go with a lower and more comfortable setting. To up supply, pump every 2 to 3 hours and try breast massage before and during. I never really managed more than 8 per day, for about 20 min each time. Have you had support from midwives on this? If not, do ask them, or you could call the national breastfeeding helpline.