BFP w/ 5 Month old son ?!?!?

Lachey

I just had a baby boy February 25th, 2017 . Had one period after delivery then nothing . Finally got pregnancy tests and both were positive ! Went to doctor and I'm currently 9weeks pregnant (hopefully with a girl) but due date is estimated for 2/22/18 . Help !!! Don't know if I should be happy or worried ???