You might assume that the expected win in a lottery, after subtracting the cost of the ticket, will be negative - otherwise the lottery would be losing money, and they don't do that. If your assumption is true then winning once, or winning twice, and so on, is pure luck.
On gambling machines you could have a price that says "all winnings on your next twenty bets are tripled". Good for you. Your expected winnings in the next twenty bets will be quite positive, and you should continue playing. But apart from such special cases, your expected winnings should be negative.
Unless... there is some programming error, or an unknown benefactor who bribed the lottery company to put money in your pocket etc., in which case your expected winnings would be positive.
Anyway, if you are on a winning streak then your assumption of "negative expectations" might be wrong, and you can proceed carefully. Just calculate the probability of winning as much as you did if everything is fair, and guess the probability that the expected winnings are unexpectedly positive.