Pregnant or not

Hi

It’s my 12th day passed ovulation and I have been having cramps in my pelvic sometimes left sometimes right and backache n been very gassy too . Did a test Clearblue one 2 days ago it was negative and did those tiny strip tests 2 line ones n it was negative .

Usually I have period on 14th but this time I didn’t have it on the usual date . Is it because I ovulated late or Can I be pregnant n not getting positive I m very confused plz help

Thank u