Period late

Hey girls so I had my period january 9 and ended it January 13. I had unprotected sex on the 14th, and he finished on my vagina. The next day on the 15th I took a plan b. A week later I was spotting for 3 days. Ever since then I’ve been cramping. I had unprotected sex January 28 and February 2, finishing partially in me. I was supposed to get my period February 7 and end it on the 11th. I’m 6 days late. I’ve been cramping a lot, nauseous, always tired, boobs hurt, I get dizzy, and bloated af. I take a pregnancy test and it says negative. But I have a friend that was5 months pregnant and her at home tests all came out negative. Any advice? Should I get a blood test or wait another week?