Is it safe to breastfeed when pregnant?

Hi.. I would like to enquire to all mothers.. my wife is currently on her first 5 weeks pregnancy. Currently our son soon turning to 7 months, still being breastfed by my wife.. Few days ago, my wife discovered spotting on her pad from brownish to reddish in colour . So we went to hospital, after checkup everything, doc advised not to breastfeed as it will create pressure to the womb and might be the cause of spotting. Any advise?