Need help

About 3/4 months ago i thought i was prego. I took $20 worth of test came out negative. I was upset of course. I was 3 weeks late. Turns out i had either a blatter infection or a kidney infection. Im still trying but my periods are starting later and later now. I used to start by the 16th for years than turnes into the 14th every month for years the same now im like 18th 20th 26th later and later ever since i had that happen and i been feeling sick but not throwing but for a good week now im scared to take a test at first i tjought maybe but i also just started my period yesterday.