A different kid of keeping up with the Joneses

This week was meant to be an incredibly productive week for me. So far it has been quite productive but hardly incredibly. Given that I'm at the mercy of other people's time table for some things, it has left me with time during the day to just wait and waste.
And this has left me with some guilt about the boys. After my student teaching ended, I took a week off. My first week off in YEARS. Then I had the unfortunate job and now I'm working on my thesis. As long as I'm working either outside of the home or on my thesis, I don't feel badly about the boys being at preschool/daycare. But on days like today when I took two naps (b/c clearly I needed them--insert sarcasm here) I feel guilty that since I have the time to parent, I should be. Because I tow the line of being both a stay at home mom and a working mom, I feel like I fail my sisters in both categories. I feel like a bit of a sell out to both groups.
Then I think about some of the other mommies I know who have children the same age as mine. Many of their preschool age children are also in preschool and I feel a little less guilty. But then I remind myself that many of them have had to deal with their husbands being deployed for years and I haven't. Once again I am back to thinking that I haven't earned this time to myself.
I also think about those moms who have more than one kid and have put their older into preschool. I managed nine months of having two at home (without killing, maiming, or even hurting anyone) and I think that if it's okay for them then it should be okay for me to do the same. But there is still that tinge of guilt that I should be parenting my own children rather than letting other people do it if not absolutely necessary. I try to compensate and make myself feel better by my wearing my badge of courage that I've never had a day away from my kids--I do not count inconsolable pain from having my torso ripped open and a child sent to a separate hospital aka the toddler's delivery--as a time off.
I do fully believe that a lot of the skills both of my children have are a result of being around other children who are older and more advanced. That I wouldn't have been able to offer them single-handedly. My preschool might still have a serious (rather than mild) speech delay if he weren't in school. The toddler certainly wouldn't be the chatterbox he is now.
One way or another, I seem to be able to justify why I should have it the other way. I don't know why I even feel the need to justify--what works for my little family should be my own privilege not my issue but maybe it's the California lifestyle or a lack of self-security but I feel the need to keep up with the Joneses.