No need to worry about making Chase suspcious. These multiple cards are strictly legit. They don't care as long as you don't apply too often within a time period. Best to leave at least sixty days between applications for an extra personal card. Business cards are apparently a different story.

In another month or so you could think about canceling the card you got in January. Best to wait six months after getting card for that. Otherwise your bonus miles could get pulled back.