I'm 28, for 2 months my period has changed to 3 days from its norm 6 days. not on bc, i have cysts & a fibroid, should i be worried about infertility?

Short periods: There is nothing wrong with having short light periods. This is likely a nice change for you from your normal 6 day pattern. We can not draw any conclusions about your fertility based on this information. There is not a link between short periods and infertility. 2 months of cycle variation should simply be monitored as this trend may not continue