Late period

My period is 4 days late today . This morning while trying to figure out what I wanted to eat I immediately got nauseous & began coughing like I was about to throw up . (That’s what happened when I normally throw up) . For 2 days now I’ve had dull cramps on the right side of my pelvic area which is causing me to think I’m starting my period but nothing has came . I’m VERY regular maybe late 1-2 days but 4 days ???? I’ve taken test and to me they look faint positive but to others they can’t see Anything . Any body can tell me what’s possibly happening ?