Is baby laying on head too often in a day?

My little girl is continuing to lose hair at the back of her head, in one area. I am worried that she is laying on her head too much. Drs have never been concerned about her having a flat head or anything.

She’s 2 mo.

Typically she sleeps on her back at nighttime and 2-3 naps a day and for a short while on her activity mat. Otherwise I might hold her for a few naps or she’s on her chair where they seems to be more weight on her butt than head!