MBC I've been on my own since I was 17 weeks pg and I told DS's dad to leave after he admitted he was seeing a minging middle aged troll another woman behind my back.
I have to say that over the last 4.5 years since DS was born, there have been really hard moments, and times when I struggled to juggle work, home and single parenthood, but I'm sure parents in couples have similar issues (plus of course, they also have to deal with and consider a partner, which IMO is added stress). However, it's the best thing I ever did. My DS has just started school and I feel proud that I got him to this stage, as a bright, polite, well behaved boy, on my own. It's an achievement. I took him abroad on my own last summer - another achievement. From my POV the worst thing is the lonliness and solitude, especially in the evenings. Once DS is in bed at 7.30pm, that's it - when you're on your own you can't go out, even if it's just to pop out for a pint of milk or bar of choc - in the evening it's either the TV, a DVD, a book or MN! And it's harder to meet someone - I'd like another child and time is running out (I'm 38) but have yet to meet the 'right' person and unfortunately I don't have a gbf to give me sperm!
If I were you I'd go for it. You've clearly considered the issues involved, although of course the proof of the pudding is in the eating. Like someone else mentioned, your baby might have colic or some other issue which will make it harder, but on the other hand, it might not. One thing to remember is that although you've obviously thought about the practical implications, until you have a baby you can never know just how much your feelings will change. Although you have a great career now, you may well decide to go part time for instance, so you can spend more time with your child, which will then impact on your career outlook and your finances.
There are pros and cons to everything and sometimes I think we can overthink things, especially life-changing things like this, and the best thing to do is just do it.