When trading Forex, the price you receive when placing an order depends on whether you are buying or selling. When you are selling a currency pair you will receive the bid price; when you are buying a currency pair you will receive the ask price. The ask price is generally higher than the bid and is different from the price you see on the chart. You can see the ask price when you open your order ticket, or you can put Bid and Ask lines on your chart in Alveo. The difference between these two prices is called the spread.
This spread is the reason your trades start out negative. When you don't pay attention to the spread you'll find that your trades seem to be closing before your stop price, or your carefully placed stop order never triggers despite the market hitting that price. The market is not combining against you to make sure you never see profits, you just need to trade using the proper prices. Remember, when buying (or going long) you will enter at the ask price, and exit at the bid price; when selling (or going short) you will enter at the bid price and exit at the ask price.
An example of this is if a spread were to be 1.00 for EUR/USD when you place a trade, then the trade will start at negative 1 PIP. If the price were to remain exactly the same until you closed the trade you would loose 1 PIP.
Slippage can also come into play in making a trade start out as negative.