Babies can pass stools many times a day. More than 3 watery stools is considered diarrhea. if baby is gaining weight and is active and playful, no need to worry. Consistency can vary too. Only if child has to strain or it's too watery, you need to worry. Teething period is from 6 months to 2 years. The weight at 5 months is dependent on birth weight of baby but a lot of variation is acceptable. You can download IAP growth charts app from Google Play and check
Next Steps
consult online if stiil in doubt