Pretty normal, he's most likely going through a growth spurt which when they are under 6 months seems to happen all the time. It's nothing to worry about, just means he's healthy. I have done so many rescues I get so excited when my babies shed. My jackson Hope, she came to me about 15 grams underweight and I'm not sure how much of that was because of lack of calcium in her bones and so they were lighter or if it was purely just fat and muscle. She has put on weight now, not as much as I expected for being 15 grams but she's supposedly full grown even though she's tiny, and just had 2 sheds in 2 weeks. Couldn't be a happier mama as I am now ^^