Algo Backtesting and Live account numbers of trades differences

Hello, 
I have problem with backtesting. 
I tested last one month in live account and backtest the same dates. In real account I have 7 trades in backtest about 20. 
Where could the difference come from?

From what I think, backtesting doesn't take into account lvl margin?
So there is not enough money in the real market to open transactions?
If im right how I can do backtesting including margin lvl ? 
I tried to implement 
https://help.ctrader.com/ctrader-algo/guides/estimated-margin/
But the results are the same.