I fed my DS throughout my pregnancy (I had hyperemesis and it was horrendous but I battled on because I - possibly erroneously - didn’t want him to feel pushed aside by the “new” coming baby).
I sort of assumed he’d wean himself as I’d read that your milk changes during pregnancy, but nope he carried on, only really having a morning and a night time feed and if he was especially upset over anything he might have an extra one.
Then when my DD was born, I definitely didn’t want him feeling pushed aside seeing her feed so i tandem fed them (!) literally from the time they met in the hospital, for another 8 months or so.
I would have never believed I would do anything like this (!) but at the end of the day, I strongly wanted him to stop when he was ready, not when I chose to stop him.
I actually think they bonded really nicely over feeding together. Sometimes they would hold hands and smile at each other as they fed which was very cute.
He eventually stopped of his own accord when we went on holiday and he was distracted by other things.
I will never regret letting him take the lead on this, I was really glad that he stopped when he was ready.
Sorry if that doesn’t answer your question exactly! I fully expected him to wean whilst I was pregnant but it just never happened!