I wouldn’t say that comma before though in your specific case is something strictly defined with a “yes” or “no”. It’s more like a personal preference. Yes, older literature is full of punctuation that depicts almost every minor pause when reading. But now putting less punctuation into the writing is very popular and some people state that it results in “simpler reading”. So it’s up to you.
If you feel like there should be a small pause before though and it needs to be visualized, then comma is exactly what you need. And if you will not use comma in some particular case, nobody will point a finger on you for that.
Here’s a piece of advice: if you really care about correct punctuation, then speak the phrase out loud. If the instinct will tell you that a pause is present, then feel free to use comma and be sure about your accuracy.