Got viginal bleeding. Viginal bleeding?

I got a viginal bleeding yesterday night between 4AM-5AM. Neither I am having my period days and nor my period has happen for 2-3 months. Actually I always have irregular periods and I have consulted many times for this issue and took medicines of contraceptive pills for regulating my cycle and it was going all well without medicines but again since 2-3 months it's not happening but the bleeding I had yesterday was not thick as period blood. It was like any normal blood thin and watery without any gel consistent moreover I am having white discharge like any other day and no red and brown discharge. I am a little concerned about this cause that wasn't period then why I am having a viginal bleeding ? I am not into any vigorous excercise or any type of intercourse.