Need help keeping current health benefits after I quit my job?

If you quit do you automatically qualify for a COBRA plan? I was planning on quiting in a month to prepare for college. Im older and would like to give school another try. However I am almost 3 months pregnant and have been with my current employer for over six months. I was going to work longer but I keep getting sick and the hours are pretty long. Im working between 60 and 72 hours a week, 6 days a week and am standing for no less than 9-10 hrs a day. Im basically a road flagging and don't always have easy access to a clean restroom. I like my employer but i don't see myself working for them too much longer. My family has been worried about something happening to me out in the field. So if I quit can I still pay on my insurance so I can keep it? Is there any other information I need to know about? Thank you all for your help.