What do you do? Will it be possible for you to return to work after having a baby (whether part- or full-time)? Are there women where you work who successfully combine a family and working.
Sad to say, but it is almost always the woman's career which suffers after a baby is born, rather than the man's, and an awful lot of employers pay lip-service to 'flexible' working but in reality it means nothing. So you need to be sure you know what you will be getting into at work should you have a baby.
I got pg (on purpose) at age 28 whilst a corporate lawyer. Bad move. I was sidelined from the moment people realised and talked about as though I was either a fool to get pregnant so young or a fool who got pregnant by accident. Returning PT wasn't an option (I knew people who had and nobody had lasted longer than 6m: 5 days work, 3 days pay, calls on your days 'off', rubbish caseload etc) and my husband's crazy schedule (also a lawyer) meant that FT also wasn't feasible unless we wanted full-time childcare (including nights).
TBH I never really loved the law and am now moving into an area I greatly prefer, so it's all worked out, but I look back at my naivety and grimace. I got pg with my eyes totally shut about the effect it would have on my legal career.
This may not be the case with you, depending on your job, and, to be honest, you may well decide that it's worth it in order to have a baby. But have a good look at what other women do, consider if it's what you want to do, and act accordingly. If there are no women at your workplace who are successfully managing jobs and children, then that should ring warning bells.
I hope I haven't scared you!! Of course some women make it work, but you need to think it through before you're pg so you hopefully meet as few unwelcome surprises as possible.