I'm a 30yr male, but I like to ware lady's underware since I'm 14yr. The problem is I'm still interesting with female(sometimes I want to be female too). Am I having a will to be a transsexual? Or is that can't be agree a man waring lady's underware?

First of all, wearing women's undergarments does not make you a transexual - it does come under the heading of crossdresser. Being a crossdress does not mean you will become a transsexual. Maybe there will be a time when you consider it. But there are many men who are crossdressers and still remain men.

Do some research on both. If you feel the need, consult a therapist. I don't see this as hugely abnormal. But if it bothers you, then seek professional help in dealing with your feelings and compulsion to wear women's underwear.

I understand Hoover liked to wear lady underwear, I am not sure of the exact term, but in the aspect of out of norm preferences this is a minor one.

Unless you want to start wearing other women apparel, make up etc... it is just a weird thing that turns some guys on.