Baby fell from bed :(

Hi all. My 4 months LO fell from bed (~ 70cm) yesterday, head knocked on floor. Observed him and he seems ok, activity all normal, feed also ok. No vomiting. There's blue black at the right side forehead where he fell and hit his head. However, today I noticed that his left side forehead seems to have a bump as well. It's slightly soft when touched. I didn't notice it there yesterday. Currently he's still behaving as per usual.. should I continue to observe or should I bring him to see doctor? :( #firsttimemom #baby #advice