Advice

Hi just looking for some advice really im 8 months pp and my periods even before birth were never really regular but since goving birth they seem to have been better. However i have not had a period since april 4th and its now the end of may. Ive done some cheap pregnancy tests and they are all negative so i know im not pregnant. No symptoms of anything really, but also no sogn of period coming either. Has anyone had this? I know they can be abit messed up after birth but i am abit of a worrier so yeah abit unsure whats going on really.