It's definitely possible, but normally when you hear of someone winning x amount per month it means that's their average monthly winnings over a longer period of time. You need to make sure your
bankroll can support prolonged downswings and you can't rely on this average monthly winnings to be there every single month. Say you win exactly $100 every month for 5 months, obviously your winrate is $100/month. However, if you win 200 in month 1, then lose 400 the next month, then win 200 in months 3 and 4 and finally win 300 in the final month, your winrate is still $100/month. Make sure you're not going to struggle to put food on the table in month 2 in that scenario.