Yes of course! Your estate is essentially your net worth – the sum of your assets less your liabilities (or debts). Your estate will change throughout your life as you acquire assets and take on liabilities so it is good to keep up with estate planning throughout your lifetime.
Your assets (which is what you own) can include savings, investments, trusts, personal real estate, and other high value goods like vehicles. Your liabilities can include credit card debt, a mortgage, student loans, and any other indebtedness.