Can you try latching baby? Baby is better at removing blockage than pump. You can also try to massage and hand express - massage in circular motion then press the lump towards the nipple. Take warm shower and massage in the shower. Usually you only need to see doctor if it's turned into mastitis, when the lump becomes red and painful and you'll start having chills/fever.
Have you try hot compression or cold compression. Try cold compress first to unblock then hot compress to kick start the milk