Aside from growth spurt, I suspect that my baby's probably teething, hence, his crankiness the last few days. How can I really tell that it's teething? What are the usual signs?

If your baby is being cranky for some unknown reason, it might be a sign of his teething.Watch out for other symptoms like if the baby is constantly putting something in his mouth, or if the gums are swelling. You may want to check this out for other signs :) http://www.babycentre.co.uk/l25007369/signs-of-teething-photos