Hey dude, I'm in a very similar situation. As of now, I've only taken Genchem1, Genchem2, Bio1, Bio2, and Orgo1 going into senior year, which also adds to a total of 22 hours of science (my university requires 2 hrs of lab for each Genchem). Taking Orgo2 in the summer, and Physics1, Physics2, and upper-levels throughout senior year.
I ended up (just about a week ago) deciding to take a gap year, one of the main reasons being that stated by Doctoothache, whereby the adcoms really wouldn't have had much to work with in terms of my performances in science courses.
But another big reason was the LOR's. Do you feel that you got to know your professors well in your bio or chem courses? Typically that's not the case, and it certainly wasn't for me. Not sure if you've already secured your LOR's, but this was a big factor in my decision at least. Of course, you've still got time to get them, an opportunity I don't have as I'm currently studying abroad.
So really, everyone's situation is different, but if you feel you'll do well on the DAT and get decent LOR's, I'd say go for it! I just felt that a gap year would allow me to touch up most aspects of my application so that I can have everything in and on time the day next year's cycle opens, whereas this cycle I really would have been scrambling to get everything in on a timely basis.