Thanks for writing to us with your health concern.
THis could be a mild bit of spotting.
It often occurs due to the drugs / injections which are given for stimulation of the egg follicles in the ovaries.
So do not worry, it is due to their hormonal
It could also be due to stress
, weight gain etc.
Just get a pelvic ultrasound
scan done to rule out that nothing major is abnormal.