First period

So... I had pink discharge Thursday and Friday, and than yesterday morning I woke up and I'm pretty sure I've started my period, my mom said that I did. But it's 2:19 in the morning and I haven't really had any flow since around 7:00 last night, i used tampons for around 8-9 hours in total yesterday( no not the same tampon). So my question is " Can your first period only last One day??" I'm just really concerned and don't understand what is happening exactly with my body.

Thanks