Hi,
Yes, I feel, that is point worth clarifying from your doctor. However, my guts feeling is that, since the medications are only affecting the motility and not the structure of the sperms, it should be alright to start immediately. A slow motility may only affect the percentage chances of successful fertilization, but if a structural damage is implied, it could affect the embryo itself. So, while you need to get confirmation from your doctor, it appears, you need not have to wait for three more months.
Solace
As an adjunct holistic treatment, you may consider doing Male deer exercise and female deer exercise. You may google the phrase for both the exercises.It will have a synergistic effect on fertility.You may also search for sexual reflexology.