Viagra Question

Hey there I just got some viagra samples from my doc so I figured id try it out before I did it with my girl cuz I dont want any suprises. So ya I popped half of a 50mg on like a completely empty stomach.

Ten minutes later I had an awesome erection felt like it could maybe be like a tinny bit better but still very good none the less. No side effects what so ever other than being a lil jumpy at first(probably because I was worried about taking it like something bad would happen).

I know they say it doesnt help desire but I tell you what I wanted my girl so bad right then haha. So two quick questions: im thinking about trying a full 50mgs tommorow night with my gal, 25 was nice and all but id rather make it even better for her, is that a good idea?

Also since such a low dosage did so much for me does this kinda prove it not so much a physical issue but psycological?

Thanks for the advice I cant wait to see my girl tommorow