Am I still testing too early?

I'm pretty positive I ovulated on Sunday 6/7 or Monday 6/8, I had EWCM both days. I used Preseed my entire fertile week. I'm irregular and my cycle is usually 30-32 days. My period is suppose to be here 6/24. I'm still getting negative tests. Is it still early for me to test? I'm 15dpo today, 6/23.