I was told by my ob/gyn (who had one for her first baby, as well) that it can take 6 months to fully and completely heal BUT there are levels of healing, e.g. no heavy lifting, strenuous exercise for up to 12wks (this is not due to scar or incision -- it won't open again, but due to possible hernia (?), if that makes sense). Also, I have noticed when it's PMT, ovulation and my actual period, I have pains/cramps not in the incision, but around my tummy (where it is still healing internally).
Obviously, other ladies here have 'recovered' quickly (I put 'recovered' in quotes in the sense of recovering to do ordinary life stuff by need and ability), but internally, it can take awhile -- if you need painkillers or to take it easy for awhile, that's perfectly okay!
I'm 3 1/2 months and have recovered well, I think -- except for some cramps around my AF/tummy and some general discomfort when I overdo it, e.g. loads of hoovering, going up and down loads of stairs, lifting heavy boxes -- I can do it, but am sore the next day (hence, my taking it a little easier the day or two following) -- we're massively spring-cleaning as was not well in the last month of pregnancy (and couldn't really clean months 6-8 anyway!)
best wishes