Is it possible that my period is missing/late because of a ruptured cyst and std or is it a chance that i might be pregnant nov 8 - the first day of the worst period i ever had .extreme cramping and vomited for the first time due to period . nov 11- ruptu

With : With a negative pregnancy test you have identified two possibilities: the ruptured cyst and the chlamydia. Another strong possibility is that you are not ovulating or that the previous cyst has prevented you from ovulating. This may be a one-time issue but cysts can occasionally recur. I usually offer oral contraceptives to women who have had "the worst period" ever and those having unprotected intercourse to offer protection against an unwanted pregnancy.