Having children, close together or far apart is your decision! I have a friend who was pregnant with her second when her first was 4 months old, and another who got pregnant after only three months! Now, those were unplanned...but another family I know has 6 children, and she was always pregnant with the next 6-8 months out of the previous pregnancy. It will be a lot of work, but if YOU want it and YOU feel confident that you can handle it, that's all that matters! And if your husband is supportive and you know that financially you're fine (by the way, if you are ok financially, maybe you'd be able to hire a nanny part time to come into your home so that you can focus a couple of hours a day into your job...), then go for it. Just make sure you're taking care of your body. Of all the objections people have to birthing children closer together, health is usually not one of them. But pregnancy and childbirth take a huge toll on the body, so even before you get pregnant take those prenatals (unless you already have been because of breastfeeding) get your water and exercise in, do your kegels!!! I would encourage you too to just make sure you know what your motivation is. I'm not assuming you're having problems in your marriage or anything like that....but just make sure you know why you want more children and that it's a healthy reason. I'm pregnant with my second and mine will be 16 months apart. It wasn't planned, but at the same time, we wanted our kids close together and weren't really using any protection and figured whenever I got pregnant was fine. So I've felt a little stressed out at times knowing I'll have two in diapers and one barely talking and walking...but being a mom is all I've ever wanted to do, and my husband and I want a big family. I also know I have a great support system with my church and family, so I'm confident that we'll be fine. Follow your gut and your heart and tell all the nay sayers where they can put their advice!
Also, I'm 25 and I know I'm young...I look at some other friends who aren't married yet or are married and don't have kids and the freedom they have to go out and do whatever they want....BUT I already have a son, so my life is already altered. I'm already in parenting mode, another baby is not going to change my life THAT much. A third might. But the way I see it, is if you're already in mom mode, then have all your babies and then when you're done, they'll start growing and you'll have more freedom as they're older...
love,
Missy