Clothes for baby between a 0-3 and 3-6?

[AnnaAli]

My seven-week-old is in the process of outgrowing his 0-3 clothes but seems to be quite a way off being able to be put in 3-6. I know Polarn o Pyret do 2-4 months, etc, but are there any other brands that do an in-between? (Preferably cheaper!) Or perhaps some whose 0-3 are particularly large/stretchy or 3-6 that come up small? He currently weighs just under 13lb and is solid but not super bulky in stature.

H&M do 2-4 month old clothes.

I find Next fit is big so your 0-3 might last a bit longer. Mamas and papas fit small so the 3-6 might fit now. And there's a brand called pitter patter I think, possibly from tk maxx that's on the small side too.
What I find handy at in between times are separates so the trousers can be pulled up a bit and the t shirt pulled down

Just try a different brand. Next tends to come up big, gap quite small.

Primark sizes always come up small so are good for the gap between sizes

Thanks - will get looking at the above suggestions!