If you are properly classified as an independent contractor and you are not paid on time, or not paid at all, you do not have the protection of the Wage Act but you should be able to hold the employer responsible under basic contract principles.
If you have a written contract, it should spell out how much you get paid and when, and you can use that to prove both the agreement and the breach. If you do not have a written contract, you can still seek recovery under an oral contract or under a theory of unjust enrichment, so long as you can prove the agreement and the services provided.
Not being paid on time, however, should trigger a question about whether your classification is appropriate. This is because if you should have been considered an employee, you can recover not just what is owed but triple damages and attorneys' fees under the Massachusetts Wage Act. An experienced employment lawyer can help you assess whether these are viable claims, as well as what your next steps should be.