well since you have got a 4 cm cyst in the one of the ovaries ,getting gonadotrophins now for IVF may increase the size of the cyst. Well this may be a follicular cyst
that may dissapear by the next cycle. you can just leave it and do a scan on day 2 of menses next cycle.alternatively you can also take the pill prescribed by your doc for 1 or 2 cycles and then do a day 2 scan to find whether the cysts persists or has dissapeared.either will help.the latter helps by suppressing your ovarian cycle and thus the impact of hormones on your ovary.
i think you have got your answer.