OP, you're not going to last long in a community of active researchers if you are unable to simply use Google. Literally, search "Heroin Half-Life" and the first search result will tell you precisely what the half-life is. I'm not trying to insult you or bring you down, but it's for your own good that you get some tough love in this situation. You are fully capable of finding answers to these questions and you do not need the assistance of the community to get them. So, the issue here is two-fold; not only does this take up space on our front page that could be dedicated to queries of a slightly more esoteric nature
and you are sitting and waiting for an answer that could be life-altering, not realizing that you could have your answer in seconds, not hours or days.
First of all, half-life is not a completely accurate indicator for the duration of action for a given drug. Heroin is a pro-drug that is metabolized in vivo into Morphine. With this in mind, the half-life of Heroin is minutes. What you need to examine is the half-life of the active metabolite i.e. Morphine. The half-life is ~3 hours, but the duration of action is going to vary widely from person to person, but you can generally call it ~4-7 hours. Unfortunately, this information, while vaguely useful, is not something you can take to the bank when you're using street drugs. As you've said, your drugs could be anything. When I was living in Kurdistan, I bought "Brown Sugar" on a daily basis and had no idea whether it was Morphine or Heroin. I just knew it got me high. That's all you know.
With this in mind, even if we knew precisely what your drugs were, which we absolutely do not, we would still be dealing with the perennial wild-card, namely the fact that every person is effected in varying ways by the same drugs. It's innate and the closest we can ever get is a vague guess at how you will be effected.
I'm going to leave this open, but I encourage you to think upon what I have said, because the answers you are looking for do not actually exist in a clear-cut way. You must do what we all have done, that is, we use our research as guidelines, but we can only truly understand how certain drugs will effect us by using them and evaluating our own experience.
Also, your question didn't make a ton of sense, but I tried