Is this exercise routine is right or i am over training my muscles?

Note: I do these exercise at home. I do, Dumbbell concentration curls (biceps) 5 sets of 20 rep after every 2 days rest (6 kg weight). Push ups up to 140+ in total, twice or thrice a week. Squats up to 150+ in total, twice or thrice a week. I have seen great results by doing all three exercise. But now i think my bicep is not growing so what do I do? Do i need to increase my dumbbell weight or change my bicep workout style? Lastly, I have started eating a lot, so I gain my weight from 58 kg to 65 kg with in 3 months and its still increasing. So, I am doing all things right? or wrong? Please answer to my question ASAP!