Suggest Treatment For A Missed Period With Negative Pregnancy Test

Hi ! I always get my period on the 28th of every mth. However, I missed my period for the mth of December. I bought an ept pregnancy test and i took the first one this morning around 10 a.m. and it read that it was negative. I took the second one around 7 :30 p.m. this evening Sunday, Jan 1st and it was negative but i still do not have my period would this test be accuarte ? What should i do ?