Further off topic still... you need to add some pulling exercises to balance your pushups, maybe some vertical pulling and pushing (pullups, overhead presses) as well, and swapping the squats for lunges or step-ups once in a while will give you better overall leg development (squats for quads, lunges and stepups will work glutes and hamstrings a bit more)

You're probably not going to run into issues with that low of an intensity (20 pushups is not nothing, but if you stop at 20 every time, it's not like you'll keep making the imbalance worse) but adding another few exercises will only add like 5 mins total to your workout, and will give better overall results