Frequent Bleeding From My Lo Nose

Hello all
Since few months, I am noticing that my sons nose bleeds often.
He is 25 months old. The first time it bleed was around 5 months ago. We immediately took him to see a doctor. Doctor said its very common in kids. Only see a doctor if it doesn't stop after 10 minutes. Its coz some vein may be bursting due to some reasons like cold and others i don't really remember.
His nose mostly bleeds early morning that makes him wake up from sleep. And like the doctor said it only bleeds for 2-3 minutes and it stops.
Also i have observed that if i have give him tylenol or if the weather is hot, his chances of bleeding are more.
The first time he bleed, we visited two doctors to take second opinion and they both said same thing that its pretty normal and only get him if it doesn't stop for 10 minutes.
But his frequent bleeds makes me worry. Also one of my close friends was telling me about a colleague in his DH office. The colleague had toddler twins and one of the twins died. When me and DH asked the reason they said that he used to have frequent nose bleeds.
This makes me more scared and worried when i see my son bleed.
Please help.