coats for winter

[WitchyWooWoo]

with it already being freezing outside i really need a coat, im 20 weeks pregnant so will need one from now till feb (due date)

don't really want to splash out on a maternity coat, so would it be ok to get one in a bigger size? can anyone recommend something for me.

not a big spender so probably in the £30-£40 price range. going to tk maxx/matalan tonight to see as absolutely desperate for one but would love to know others experiences of buying coats when pregnant.