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is more of a mental hurdle than a physical problem.It is a problem that comes on due to mental stress;tiredness;work pressure;depression;to name a few.See whether you have any of this.Also to increase the time you can do kegel's exercise (ask doctor
near you to explain it) to strengthen pelvic muscles or start & stop method ;where in you need to stop before ejaculation & after the desire of ejaculation subsides again restart sex.Try these methods to increase the timings also do more foreplay before doing intercourse and as you said it will help satisfy your wife.The second part is to get pregnant;if the semen analysis
shows good amount of motile sperms (more than or equal to 50 %) then there should be no problem to get pregnant if your wife's reports are normal which a Gynaec doctor will examine & tell.
Hope this answer helps to guide you properly.