If you keep doing what you were doing to get it in the first place, than yes, it'll probably continue to get larger.
The one I had in my groin started out with just a tear, and no bulge. Within 6 months the bulge was the size of a grapefruit and was pushing against my right testicle.
The location of yours, is much less painless, so as long as it's not strangulated you should be OK for awhile.
A strangulated hernia is were the intestine is pushed through the abdominal wall (muscles and lining) and gets stuck there from the tension of the muscle. This is very serious and can cause gangrene and death (worst case scenerio - and rare). Lay down on your back and relax, and GENTLY (don't rush it) try to push the bulge back inside your abdominal wall. If the bulge goes back in it's not strangulated. If it's stuck outside the the abs then you'll want to see a doctor immediately - even without insurance.
Not trying to scare you, and I'm not a doctor, but I have personal experience that I'm sharing with you.
Hopefully someone with more knowledge will contribute to this thread, and you'll have a different perspective to consider.
A dark brown stool might be a matter of concern also - if by dark brown you mean black, or near black, that could mean bleeding in your digestive tract - also a very serious problem.
Try to find a county medical facility near you that you can go to in if this becomes an emergency. They'll (at least in Nevada) help you even if you don't have insurance, and will let you make payments on the bill.
God bless.