Period changes after breastfeeding

I breastfeed my son for 13.5 months and then it took a few months to get my period back. I have now had two cycles since it’s return and they have been longer ( before I had like three days and now it’s been closer to five with days of spotting after). Just wondering if this is something other women have encountered? Also will this make it harder to conceive? I have been trying for 7 months.