I need to ask few more questions before answering your query. Early consultations can prevent complications. Kindly contact me on whatsapp chat  (84960595 six five) Dr Faisal Zoheb MBBS , MD PAEDIATRICS , PGPN (BOSTON), FELLOWSHIP IN NEONATOLOGY ( Newborn and vaccination specialist )

This is a normal gap in the bone called anterior fontanelle. It fills by 1.5 years of age. Bulging is normal during crying and staining. But please confirm by getting a check up by a pediatrician

No worry

This is normal only Do not worry

If the swelling appears only while crying/straining and becomes flat when calm, active and feeding well, it is often due to normal prominence of scalp veins or soft tissues. However, an examination by a pediatrician is advised once to rule out conditions like a small swelling/cyst or fontanelle-related issue. Seek urgent medical review if the baby develops persistent swelling, vomiting, excessive sleepiness, fever, seizures, poor feeding, or if the swelling becomes tense/hard.