Im 18 sometimes in my ovulation i saw dark brown or blood mixed is it normal from the last 6 month i saw that the 3rd time i made smir test it was ok?

Normal: Leading up to ovulation, there is a normal rise in estrogen levels. With ovulation, there is a brief, abrupt drop in estrogen levels that sometimes leads to a small amount of mid-cycle spotting. This can be seen as bright red blood or a brownish discharge. This sounds like it fits pretty good as an explanation!

Yes: Mittleschmertz is light bleeding in the middle of the period, right around the time of ovulation, so if that's what you mean, it's normal.

Probably ok: Bleeding patterns and appearance of the blood can vary a lot. It most likely is normal occurrence. But if you have unusual pain, burning, or odor, you should check with a doctor to see if everything is normal. You will have peace of mind.