Oral sex with gf. Please anyone say?

Me and my gf had oral sex. But I always used to wear mask Jean and innerwear on that time. After sometime I've seen wet near my thigh. She said it is due to her fluid as she is not wearing anything on March 6. Later she haven't got periods on March11 which is her due date. After two she took pregnancy kit test on 26 and 28 both were negative. On 28 March also she took ultrasonography of abdomen and pelvis in scan centre by saying reason as irregular periods. In report impression it is typed as left polycystic ovary other than that everything is normal in size only left ovary has multiple follicle. She took that report to our nearby gynaecologist. She seen only information. But she not seen the ultrasound image. And she gave 3tablet for 20 days and said to take continuously after taking that only periods will come she said. Other than that she said there is no problem only some cyst in left ovary. But she not seen ultrasound picture. What to do we were still scared. Please anyone say???