Cycle help

hey everyone ... currently ttc... my cycle is 35 days long. and at cycle day 14 I always have light bleeding for 3 to 4 days .. almost like a mini period. my doc did blood work and everything checked out fine there...... I do have hypothyroidism but am medicated and it's normal . not sure what is causing the mid cycle bleeding but I'm thinking this might make me not be about to conceive ... anyone gone throu this and have some insight.