Orgasm????

Hey girls I need to ask a question!
So when we have sex if my SO does something that feels good I tell him to keep going-I start to feel REALLY good and tingly down there and enjoying it loads but then it just stops. Literally goes to zero in a split second!
Does this mean  I've orgasmed when I was feeling good? Or not? Is there something wrong with me, can I even orgasm? Or do I just need to keep going and it will come back again? 
Please answer cause I'm beginning to worry! Thanks!❤️❤️❤️