Trades on the Exchanges operate on a 'first come first serve' basis, following a queue system. This means that if multiple orders are placed at the same price, and there's only one opposing offer, the execution prioritizes the earliest placed order.

Understanding your position in the queue at any given moment is not possible due to the rapid changes in numbers and volatility on the exchange. The vast number of orders being added or reduced in the queue in a split second across the Exchange participants makes it unpredictable.  Exchanges do not provide orders based on the queue but shows the total quantity and no of orders for a particular price point only.  Hence even though you have placed an order at a particular price at which there was a trade post your order, your quantity may or may not get executed based on the above principal. Please note that in case the trade price after your order placement has breached your price than your order would have got executed.

Exchanges adheres to a "price-time priority" principle for both orders and quotes. Each order receives a timestamp upon placement, determining its priority in the execution queue. This system ensures fairness and efficiency in processing orders.