Apparently “Glee” was wrong. Mono isn’t the kissing disease. Pink eye is.

When E. woke up yesterday, her left eye was a little red. I thought it might just be allergies. She wasn’t really rubbing it or anything.

We went on with our day, going for a nature walk at one of our favorite state parks (more on that later), but the eye kept getting worse. Then, green goo started coming out and it started looking a little more swollen.

Still, I thought maybe it was either allergies or perhaps she had gotten some sand in it the night before while playing in her sandbox with her friends.

By late afternoon, though, I was getting worried enough that I made a game-time decision — we headed to the urgent care center. The one I wanted to go to was about to close, so I ended up a different one. In the 15 minutes it took to drive there, E. passed out in the car.

She must have been really tired because she stayed asleep while I took her out of the car, went inside and completed the registration process and even during my gasp when I learned it was a two-hour wait. Then I was really glad she was sleeping because the last thing I wanted was my sick toddler running around the urgent care center touching everything she could get her grubby hands on.

But we lucked out — we only had to wait about 30 minutes and she woke up as they were calling us back. Again, fortune was in my favor because normally she’s a bear when she first wakes up but she was actually pretty pleasant.

After waiting a bit longer, the doctor came in. I’ve never had great experiences myself at urgent cares but this guy was great. Pretty young and really good with E. Before he even looked closely at it, he said, “Yup, it’s pink eye.” By this point, the green goo was practically pouring out.

He also taught me two important lessons:

• Allergies or environmental irritations are never in just one eye. It’s both.
• If it was an irritation, the drainage would have been clear

He prescribed some antibiotic drops and we were out the door. The drops need to go in every four hours for 7 days, which isn’t that fun.

But, he said as long as the eye looks OK on Tuesday she can go back to school (that President’s Day holiday actually falls at a convenient time).

Surprisingly, by this morning, the eye already looks SO much better. No more green goo, the pink is gone and the swelling has gone down a lot.

I called the girl she played with on Friday, and so far, no symptoms. My pal said it’s a bit like a toddler STD — I need to call all her playmates to warn them to be on the lookout for symptoms.

I’m blaming her kissing partner for this one.

I’m just glad that our first trip to urgent care was warranted and not just me being paranoid. Still, it’s not an experience I’m looking to repeat anytime soon.