My 3 months old baby always sleeps by his tummy? Is it ok to allow him to sleep at night like that ?

It is always important that you follow safe sleeping guidelines with your baby – but if your baby will be spending any time sleeping on her stomach, then it’s crucial. Your baby should sleep on a firm surface that’s covered by a tight-fitting sheet. There should be no loose bedding, soft pillows, or stuffed toys in your baby’s sleeping area. It’s safest if your baby is sleeping near your bed (so that you can keep an eye on her). Try running a fan in your baby’s room. Co-sleeping is not advisable but that is what I've been doing with all my 4 kids and they are all growing very well : )