please help?

i’m nearly 8months pp, period have always been on time since around 8weeks pp, my period was due monday 14th december and still not arrived, making today the 6th day of been late!! i did a cheapy home pregnancy test yesterday but i’m almost certain that it’s a big fat negative😰 i’m also having a lot of this clear/milky very stretchy and gooey discharge which is very unusual, please can anyone help??