The preferreds always drop after ex-dividend day as you may well know, but there are two schools of thought here:
Buy some now, hold back on some to see if the preferreds fall more next week. If they do, buy more.
Hold back for now, the nonfarm payroll jobs report is coming on Friday of next week and the markets may react one way or another to that. If the markets go down, a better buying opportunity may arise. Of course, the markets may go up after the report also. It's a tough call, but there is no need to hurry for now since any further dividend is another three months away from this upcoming dividend.