ocps are not harmful. Were your cycles regular before the first childbirth? Maybe the ocps have uncovered a hormonal issue, due to which the cycles are irregular. If you want to stop them, simply stop taking them, and body will get back top normal in 2-3 cycles. Neither the ocps or the tranexa will harm you or the baby.
Try to see a gynaecologist
for a pap smear
test to rule out cervical issues for foul smelling discharge. This is not due to the ocps. Hope this has helped. Send me any further queries you may have.