Momof2,
From your posts, you are obviously intelligent, so I think you're perfectly capable of doing well on the MCAT if you prepare and approach it correctly. Don't sell yourself short. Test-taking is a skill that can be taught--yes, some people are naturally better "test-takers" than others but that doesn't mean you can't improve your skill at it. It sounds like your problem is that you are too slow in reading the passages and answering the questions. That is something that can be fixed! It doesn't sound like the problem is with reading comprehension. Perhaps, also, you are too careful and thorough in answering the questions and it slows you down; you may need to learn to be less perfectionistic about it. I really believe that courses such as the Princeton Review can be very helpful in teaching test-taking skills such as how to quickly read a passage, how to eliminate wrong answers by process-of-elimination, skimming passages, etc. and I would strongly encourage you to look into such a course--perhaps even get some private tutoring from them just in test-taking skills and how to approach the test. You also need to start believing that you CAN do well--if you're anxious during the test about how you're going to do, you won't do as well as you could if you feel confident.
Finally, I definitely agree that if you're having labor pains during the MCAT that is a major distraction and could seriously affect your performance even if you weren't aware of it at the time! Take it again, after ample preparation (maybe wait till next April so you have plenty of time to prep), kick the MCAT's butt, and then at your interviews you can explain that you were in labor the first time you took it! Adcoms will surely understand that and excuse your low score, as long as you do better the second time.
Don't get discouraged! Good luck!