When should I test to see if I’m pregnant? We didn’t find out I was pregnant with Ivy until I was 20…

When should I test to see if I’m pregnant? We didn’t find out I was pregnant with Ivy until I was 20 weeks. My period was supposed to start yesterday but I didn’t and it doesn’t feel like it’s going to start anytime soon......I took a test this morning but it was negative. We had sex a couple times around the time I was ovulating but we used the pull out method.....and I know you can get pregnant from pre-cum