Missed period

Okay, so this is my 3rd day of a missed period, I'm extremely tired have been sleeping all day, I'll crave a food but once I eat it I get sick and want to puke, tmi but I've been kinda constipated too and I've taken two or three pregnancy test and they came back negative. Should I wait longer to take them or has anyone had this problem, Any advice or opinions would be helpful! Thank you in advance ☺️