Do I need to change the oil this soon?

The previous oil change was done a few months ago. The oil change sticker the mechanic placed on my window was to change the oil at approximately 188,000 miles. But currently I'm not even close to that mileage. My vehicle was low on oil, and I put under half a quart in already a couple of days ago.

My oil sensor is going crazing saying I need to change the oil. Again, I'm not even close to the mileage the previous mechanic wrote to change it.

I can upload a picture next time if that helps. I will get my correct mileage too. I drive locally. I'm not sure the exact mileage I drive but probably under 4,000. As I last had synthetic oil change. And previous oil changes were conventional, which I was told wouldn't last as long. Synthetic seems good but is expensive if I don't drive far or long distance. A local Jiffy Lube I called told me conventional oil is going obsolete. A few places locally still offer conventional $30-$80. I'm not sure why some places are more costly than others. Maybe overhead?