15 days late period ;0 I got negative pregnancy 5days ago


I had pregnancy test 5 days ago with my second urine at 6am. I wake up at night few times because the weather is too hot. On 24th of July, I woke up around 3 but I forgot about the test, so I slept three hours more to get tested again without patience for the next day. Then I got *a clear* negative result. The test kit is for early pregnancy detect with 99% accuracy. So

To make sure whether or not I am pregnant, I checked with my cervix that it's high and firm. I read from online when pregnant, the cervix should be high and soft.. but mine is firm :0

I have no idea.. if I am having a missed period or not. Because, in order to have period, the cervix should be low...by now?

I want to know if anyone experienced getting easily angry and irritable after missing a period or before having late period for 15days.