why do girls stare at me

im genuinely confused and terrified most of the time. In class or sometimes just on campus I catch girls giving me like a long stare and i don’t look back except for a second because it’s really weird. I don’t know if this is a good or bad thing because they’re not always smiling but aren't snowing like disgusted faces either. 

I am so awkward around women in general whenever I get a compliment I just freeze and “😃 thank you” then walk away and my inner monologue is like “why didn’t you compliment them back” so I end up feeling guilty.