Need advice!

My son is a year old. Since I gave birth to him my cycle day lengths have been 33 days on the dot. Last cycle things change and it was only 25 days long.

We are trying to concieve again, we had sex alot!!!!! And we did it during ovulation time.

Im on CD 30, still nothing and I took a test yesterday and it was BFN. Don't feel like I'm pregnant... So when should I expect my period...?

Also, when I got my positive OPK, I counted the days and I should start today.. anytime..