Teenager problem

So I'm 15 and my period is late and like 2weeks ago I hooked up with a guy that is a year older then me.He only put the tip and he used a condom,but after he did that I ran out of my birth control pills and I have been really hungry and when I eat I get nauseous and my breast don't hurt and I'm barely tired.My mom isn't letting me go back on my birth control pills but I feel like if I go back it will fix most of this...so can someone give me some advice please🙏🏼🙏🏼