Strong Program - Too easy/short?

Hi, I’m currently on day 11 of the Strong Program. So far it’s been relatively easy with the exception of the first day. I guess my concern is that I’m not feeling sore or too tired after my workouts. I’m unable to increase my weights at the moment (I only own 15lb & 5lb dumbbells). Is it a good idea to add an extra video to increase duration? Should I add more strength training videos or lower impact?

Edit: I took advice and went slower. Yup! I've changed my mind. It's only too easy if you're not challenging yourself. Thanks guys :)