Hay, honestly depende sa gaano ka-active ka before pregnancy, if nagbike ka na regularly, usually okay lang to continue, pero talagang kailangan mo i-check with your OB first kasi ang first trimester ay sensitive pa talaga, lalo na kung hindi ka sanay. I'd ask your doctor kung safe pa rin in your case, especially since balancing at possible falls ay risky talaga pag buntis, kaya mas better safe than sorry! Sabi ng OB ko noon, low-impact exercise is best, so maybe gym bike or stationary bike nalang if gusto mo talaga mag-exercise, but your doc can give you better guidance based sa situation mo.