so... using fertility drugs for x number of cycls will not increase your fsh level. The fsh level is dependent upon the ovary's responsiveness on a particular cycle. In fact, fertility drugs consist of FSH/LH which are naturally occuring hormones already in circulation in your body. Adding more does not impact the ovaries. Remember, FSH comes from your pituitary... not your ovary. It is released in response to the E2 levels produced by your ovaries. The fertility drugs do not act on your pituitary in any way as the pituitary does not react to FSH.
You will find that your FSH level goes up and down under normal circumstances. You will often have several cycles where it is low and then one or two where it is elevated. This happens with or without drugs. It is part of our nature to try and put cause and effect on things. Since most doctors only do stim cycles when FSH levels are low people naturally conclude that doing several stim cycles with low FSH and then having a high FSH cycle is a result of the previous stim cycles. It is not. Hope this answers your question.