need advice

Kelly • 33 mum to 3 boys 6, and twin 4yos and engaged to my wonderful fiancé ❤️❤️
Ok I'm 4months pregnant and this past 2 days I've had some pain it not unbearable just uncomfortable and mild like muscle aches in my tummy this is my 2nd baby and I can't really remember feeling like this with this first so early on..I'm quite big for only being 4months..just wondering what the pain could be or is it just baby growing! TIA xx