3 month old throwing self back

[Girlmum0609]

Just that really. My 3.5 month old keeps throwing herself back in my arms or arching back and straightening legs on her mat. It’s accompanied by crying so I’m thinking frustration or pains but I’ve googled and I can’t help worrying.
she doesn’t go vacant or stare, its always a sad face and a cry, she can get a bit red until you pick her up or reposition.
Did anyone else’s baby do this around this age?

We’ve had some trouble with upper body tension which we’re doing physio for at the moment. She’s gone from enjoying time on her mat to hating it and same for tummy time which really isn’t successful atm. my mind is racing…

That sounds very much like silent reflux. Poor darling. Arching the back is crying. Is it within half an hour of a feed?

Arching the back AND crying, of course that should say!

We have her on anti reflux milk and it’s been 2 hours since her feed. She doesn’t spit up or seem uncomfortable on the bottle at all.
can reflux take 2 hours to cause such discomfort? I thought it was frustration or tiredness, when I mention reflux to the GP because she doesn’t spit up or have any other issues on the whole they say it’s likely she doesn’t have that however we switched to anti reflux early on.