Period

So I had sex on the 11th an my period was supposed to start on the 14th an it isn’t here. Remind you my boyfriend did not cum in me I made him stop because it felt weird. My period isn’t here still today but I am bloating,sore boobs, light cramps. 2 months ago I had a period that was three days late then last month I had my period two days early. I don’t know what to do and everybody keep telling me it’s because I’m stressing. I took a pregnancy test and it came back negative. What do you girls think? Little advice or help?