What do I do to confirm? Being pregnant?

The last month I was having my period was during Navratri, that is after 10th of October. And yesterday, I got intimate. We didn't have sex. But he wasn't wearing a condom to stay on the safer side, either. And yesterday only, during the late evening, that is at about 8 o'clock, I got into my period. Yesterday night it was a heavy flow. But RIGHT NOW, it is comparatively lesser. I'm just worried. I don't wanna be pregnant. And NOW, I can't even take a contraceptive because I am on my period. What do I do? I can't even tell my parents about this nor can I consult a gynaecologist on my own. Please suggest me what to do. PLEASE. Are there any chances of me being pregnant? Please guide me. A detailed reply would really be appreciated. Thank you so much.