TTC after chemo treatments

I went through chemo a few years ago and am now healthy enough to try for a baby. My husband and I have been trying for a few months but keep getting BFN. AF comes 13-16 days late each month lately getting my hopes up and then crushing me when I finally get AF. Before deciding on trying for a baby my periods were always on time every month. Anyone else go through this or have tips on TTC? My doctors gave me a very low % of every having a child after going through chemo treatments.. Thanks for any comments or suggestions!!!