Mommy guilt

Mommy guilt is a concept that I've heard of several times through various blogs and parenting websites that I read.  I never have really felt a lot of this so called guilt that many mom's have talked about.  Sure, I have things or situations with James that I occasionally wish I had handled differently.  And while I am certain of our family's decision to be a "two working parents" sort of household, I do sometimes wish I was home with my boy, watching his every milestone occur in front of my eyes.  But really, for the most part I am comfortable with the fact that many of the parenting "plans" that we made before James came never came to fruition.  I had a unplanned, quasi emergency C-section 5 weeks early and wasn't able to breast feed mainly due to this fact.  We didn't really let James cry it out.  We didn't use an many attachment parenting techniques as I thought we would.  Some moms have gone on and on about their guilt regarding these things, but I really don't have it.  I also don't think C-sections are evil, but I won't even get into that one.
James and I are alive and really that's good enough.
But for the last few weeks or so, I have had some mom guilt creeping into my head.  Leaving James for 4 days to go to California for my Grandmother's funeral started it.  I felt horrible about leaving James and Adam, even though I knew it was for the best.  Travelling cross county alone with a toddler is not on my list of things to do...  Like ever.  A few weeks after I got home, I attended a party at Jackie's house, again solo.  Then I went to another friend's baby shower, again alone.  And tonight I am meeting a friend, Tisha, who I haven't seen in years for dinner.  James isn't left with a baby sitter for these events, Adam is more than willing to stay home with him, but its weird to feel so bad about it.  I know that Adam misses James when he attends football games during the season, but I don't know that he feels the same kind of guilt that I do.  And maybe that's the first indicator that I shouldn't feel this way and am putting pressure on myself.
I think the root of this is really the feeling that I do miss a lot because I'm not home with James during the day.  We try to make the best of our short hours together at home during the week and do fun things on the weekends.  That's not always possible, like this weekend when we will be going to get eye exams.  After work turns into a marathon of dinner, bath time, play time, story time.
There is a fine balancing act to this whole parenting thing.  I need to be near my baby as much as possible, enjoying every moment of his childhood, but I also need to maintain some inkling of who I am without being just James' mom and Adam's wife.