I'm getting them weekly, I currently have one in each boob 
Ds is 7 months and I didn't get them to start with, but have had them frequently over the past four months.
Sometimes I can pinpoint a reason, eg I might wake up half squashing my boon between my arm and body
and it'll be blocked or ds might have gone longer between feeds (that's why I have them this time) but other times there's no reason. Sometimes in the same places, sometimes not.
Latch appears to be fine no pain apart from on the bloody milk bleb I can't get rid of despite trying everything including needles
he is at that age where he frequently pulls off to look behind him though 
It's really painful and really starting to get to me I want to keep feeding but this is making it hard. Any advice would be great 