First pregnancy need to be reassured

Hii I’ve been experiencing cramps pretty much everywhere (mostly lower abdomen) on my stomach , lower back pain and also feel nauseous feeling like im about to through up (gastric reflux) I just want to be reassured is it normal ? Should I be concerned? This is my first pregnancy and I’m now 19 weeks and 4 days and I’ve never felt this way until now..

(can it be because I lifted something to heavy because I went to the grocery store didn’t use a cart and carried a bag of 16 kg bag of dog food a small bag of cat food and a 5L laundry detergent bottle.. )