There is no normal level of libido. It can vary from person to person how much is enough. Increase sexual activity is unhealthy when:
1. It interferes with your other daily activities.
2. It becomes an obsession that triggers compulsive behaviors to perform sexual acts. This means you are aware that you shouldn't be doing that but you did.
3. When you want to change your sexual habits but you have difficulty doing so. Shifting from frequent to less frequent sex.
It's not healthy if it interferes with your daily priorities and you tried to change it but have difficulty doing so on your own.