Dear service user
Thank you for contacting Healthcaremagic.
Hi, I have gone through your question and understand your concern regarding too soon ejaculation during sex with your partner. You reach climax earlier as compared to your partner so, she doesn't enjoy climax at all leading to frustration.
Dear friend, don't get disappointed.
There is neither 'specific' time period nor number of strokes defined for ejaculatory delay. It greatly varies from person to person.
This happens sometimes for men, when they start sex with a particular partner, the initial arousal level is very high so he reaches orgasm quickly and emission occurs. But, this situation gradually declines over a period of time. Hence, if an individual is reaching orgasm/climax early, he is likely to experience a little delay in subsequent encounters.
When clients with similar problems approach me, I recommend them a behavior exercise called start-stop technique. The man starts masturbation and stops just prior to orgasmic inevitability. He allows arousal level to decline and re-stimulates. One should continue this 'start-stop' sequence for about 15 minutes.
Later on he may do similar 'start-stop' exercise with partner during sexual intercourse stopping just prior to ejaculatory inevitability.
In this method, man learns to identify or feel the point of ejaculatory inevitability (The point of NO RETURN) and gains voluntary control of ejaculation gradually over a period of time.
Hope, I have answered your question. If you have any further questions I will be happy to help. Wish you good health.

Dear service user,
Thank you for writing to healthcaremagic.
I understand your concern for premature ejaculation.
For constant erection continuous exciting/romantic/erotic feelings should be there in mind. If mind diverted to concern about erection/ejaculation, ejaculation occurs fast.
Erections at work place do not suggest any disease. Relax.
When clients with premature ejaculation come to my clinic, I recommend them one or more of the following strategies which often help them.
1. Stop-start technique of behavior therapy.
2. Female on top with active role.
3. Double condom
4. Medicines like Fluoxetine 20 mg day or Paroxetine CR 25 mg per day.
(To be taken under medical supervision only)
5. Kegel exercise also helps in some cases. You can learn the same from internet. (As if try to hold urine intermittently during voiding)
6. Penile squeeze technique applied at the point of ejaculatory inevitability.
7. Applying a local anesthetic ointment to glans penis prior to penetration.
8. Leading partner to orgasm by exploring and stimulating other erogenous zones. (Other than vaginal containment movements only)
9. You should do masturbation before sex (at least 2 hours before). It will make seminal vesicles somewhat empty. So, at the time of sex, semen will take more time to come out.

One can gain ejaculatory control over a period of time by practicing behavior methods mentioned above REGULARLY. Practice makes a man perfect.
You can consult psychiatrist or sex therapist for this. Wish you good health.