I don't think you need to worry
Anytime you put your penis inside of her without a condom, you risk pregnancy. Doesn't matter if you ejaculate or not as the penis can let off small amounts of pre ejaculate which is plenty to impregnate a girl. However, way too soon for any symptoms that your girlfriend is mentioning. And mostly, it doesn't sound like she's pregnant. If she doesn't get a period, she can test with a home urine test the first day she misses it. good luck