rachel i used those tesco ones last time, and got the same ones for this time. i think i got 3 packs of the big ones, and then a couple of packs of the thinner ones for later on when lochia is less, i really can't remember how many i got through last time though, but tescos is between the hospital and my house, so DP can always nip in there if we need more than 30 big ones! and like you say, at £1 a pack, they aren't breaking the bank.
Good news re your window.
And yes, being pregnant in summer isn't fun, DS was a November baby, and so this is my second time, but it was on purpose as we were aiming for a Sept onwards baby re school years, but still sucks! I have a fan on in our bedroom more often than not, and it really helps to cool me a bit at night. Just wish i could sit in front of it more in the day, but DS would get very bored if i did! I have lots of ice lollies in the freezer, rapidly dwindling in numbers though!! Current favourites are from tescos, £1 for 10, cola, lemonade and raspberry mixed box and quite low in calories, although don't like raspberry so DP will have a few of those to eat! And co op do a £1 box, but only get 6 in it, pineapple, orange and blackcurrant, the pineapple ones are very moreish!