Good numbers or miscalculations???

[Gary Chapman]

I'm a new investor with one property in my portfolio so far. I want to invest in another property and so have been really crunching numbers and analyzing my last investment. Honestly, I'm feeling a bit confused about my calculations and either feel like I hit a jackpot or am missing a big piece of this puzzle. I'd like to share my numbers to see if I'm calculating correctly or not. Property is a duplex. 

Purchase price $236,000

Downpayment $70,000

Renovations $70,000

Monthly Rent $3600

Other income $300

Total Expenses $13,350 (taxes, insurance, utilities, maintenance)

So if I'm not missing anything I'm seeing a cash flow of $19,410 which would be 800/door a month. Everything I'm reading says 200/door is good, what am I missing?