Sheena, after 2 c-sections in just over a year, a spare tyre is pretty standard... and its the devils mission to get rid of too!
I was a 14 when i got preg 1st time around, and suddenly put on a lot of weight in the last 10 weeks and ended up a size 18-20. By his 1st birthday I'd put any weight lost during birth back on again.
2nd time around I was in the process of losing weight when I got preg, but was still at least a size 16, and am back to an 18-20 (was drinking complan and eating all sorts to try and make BF work, but she wouldnt feed, so all that extra stuff went into the trunk

) But now that jae is having longer awake periods, and I have a 3 wheel pram, i plan on going out for runs (well... walks to be a bit more realistic lol!) while B is at school
I had a friend who complained about being chubby all her life (she was maybe a 14/16 pre-preg) but I saw her for the first time since she'd had bub (I think he was about a year old?) and she looked anorexic! She swore it was just from BFing but I dont think I have ever seen anyone lose that much weight just BF alone...?