Like Blue said, practice going slower. If you feel you are going to ejaculate, stop until the sensation passes so that you can continue. If you masturbate, you can practice this alone too (slowing down and prolonging). It's very common at first to not have much control, but with practice and good communication with your wife it will get better.
How long you been married..?
If you are newly married and never had sex before then dont worry.. You will learn by time..
Dont go too fast..
Try to hold yourself when penis is inside vagina and move slow.
Once you have control in begining then you you can stroke little fast ...
after practice you can go 10 to 15 minutes easy and so on..