I have lit period and no blood clods, and cramp really bad when I start by period. I also sometimes have pain when I have sex, I been married for 6 years and yet to conceive do that have anything to do with why I haven't

You appear to be having other issues besides conception I will briefly address them.

Sex should not be hurting, unless you are doing rough sex.
And are into pain. * some people are and if that is you thing, fine.

But if that is not the issue, are you having enough fore play to have proper lube to start ?

If those are not issues, and does not fix issues, please see the doctor, there may be other problems.

Next are your periods regular, and if so, are you tracking the proper dates you are most fertile. So you are timing sex for the most or best times.

You need to go to a doctor and ask them that question.Most communities have a free woman's clinic and you need to speak to them.No one can answer that question here because there could be many reasons you have not conceived.
Planned parenthood is in may states.I would see if there is a Planned Parenthood in your area and start there.They have free health care for those that can't pay.

I have serious issues with Planned Parenthood and would not recommend them personally to anyone.