Negative Test & Late Period

Jordan

This is our 4th month trying to conceive. I’ve tracked my periods for a very long time so I know I’m accurate as far as ovulating bc of tests etc. I’m currently 15DPO and my period was due yesterday the 26th. I took an easy at home pregnancy text bc that’s all I had on hand and it was negative. Just wondering if it has taken anyone else a long time to get a positive test and is it common to get negatives right away? Should I go get a First Response and test tomorrow or wait a few more days?!