Applying for a new credit card within 5 months of the last

Hello,

So I got my first card (as an authorized user) in February of 2015, then got my first personal card in July of 2016. After that, I opened another card in February of this year.

The thing is, my spending categories are generally food and online purchases. My cards (excluding the authorized user one) are Chase Sapphire Preferred, and Chase Freedom. This covers rotating categories and travel + food, but I'd like a flatrate cashback card to cover the other categories, like clothing or shopping expenses.

It's been nearly 5 months, would it be ok to apply for a new card? Or am I opening cards too fast and should wait longer? My credit score is 750 and my combined lines of credit are $22,000. I currently have two hard pulls on the account from the two cards, no derogatory marks, and I've never missed a payment.