Help!

Ladonna • I`m 21 and I`m ready to get my life back on track and I feel like this will help me=)
Okay I haven't had my period at all this month and I am now three days late.....I took a test last night and it was negative. I don't know if I'm pregnant and I don't know when I should take another test. My partner and I had sex on the 8th of this month and that was my ovulation date. I was 33% likely to get pregnant on the 8th. And am I testing to early?