Attention from strange men...

So I work for a large company and there are probably over 400 employees at my location alone. I've noticed lately and since I really started showing, that guys (especially guys I don't know, of all ages) are just giving me more attention. Nothing inappropriate, literally just smiling as they walk by, or asking "how are you" or saying "have a good night". And the guys I do know make a point to ask about my due date, gender, name, etc. anyone else experiencing this?? If so, how does it make you feel?