biking while pregnant: when did you have to stop?

🇳🇴ES🇳🇴🇮🇸
I bike almost every day as part of my commuting. It's either on sidewalks, bike lanes, or very slow residential streets, not in traffic, and I don't go very fast. 
I'm now 14 weeks and not really seeing much difference in my body, so I'm wondering when people who bike regularly have stopped out of balance concerns or because it was too difficult to lean over the bike with your belly in the way.