Check this.

Curdled milk is common its extra feed he took, spitting milk also ok, if he does not feel any discomfort then you should stop worrying.

@Ritu: he is spitting up plain milk too. I will visit Paediatrician asap. He looks fine though. Sleeps most of the day but night time is for playing n crying for no reason 😒😒

So curd is good - shows feed digested.

You can analyse what exactly it is..if it's curdled milk in whatever quantity. It's okay! If it the plain milk vomited with force more than thrice a day,you need to see a doc. If it's regurgitation,you can help by elevating the head a little. See if it gets better. And you will find tonnes of material online. Better go by mother instinct as so much info on the net can be confusing. When in doubt that your lo is not fine,plz see a doc.