Agree with Anna8888. It's about the fact that you have a choice!
It's hard to advise you without knowing you and being able to try and second guess how you'll feel and how you might feel about struggling to get back in the workplace.
I went back for 2 weeks after ds1 and then gave up. However, my old company have kept me busy on a freelance basis ever since (I left 6 years ago and now have 3 children!).
My gut reaction is to say go for being a SAHM - I can't believe how quickly the baby/toddler years have gone (ds3 starts school in September) and all I can say is that I am 100% certain I did the right thing. That's it, a chapter gone, but at least I didn't miss a moment of it.
Once they get to school - that's when you really see the benefits of being at home (imo anyway). No issues if your child is sick, if they have a production you want to go and see, no problems doing school runs etc.
Although I guess it depends what emphasis you put on those things too. To me it's hugely important that I'm able to take mine to school and pick them up and take them home/to friends/to activities at 3.30 and that I can do homework/reading with them at a reasonable hour etc. For some people using after school care isn't an issue but it fills me with horror.
Anyway, I ramble. I guess it's impossible to know how you'll find staying at home so all you can do is give it a whirl if that's what your heart is telling you to do now and you can afford to do so. 6 months down the line you may be ready to go back and you won't have been out of hte loop for too long. Conversely, you may love it and realise it's the best move you ever made, in which case, you won't care about the career you left behind most of the time (I have fleeting moments where I think of the money I could be earning, the benefits I'd have blah blah - but 99.9% of the time I couldn't care less because none of it is as important as what I've got).