When we calculated Small business / self- employed estimated taxes for tax year 2017 we only used the income earned by our small business, is this the correct process?

We are trying to determine for this taxable year[2018] estimated tax on our small business. We have reviewed 2017 estimated worksheet, it was solely based on the small business income made in last quarter of 2016. We need help and would like to speak to someone live on the phone, phone number is (removed). Thank you