Is it safe to use tampons, if I have been having a lot of blood clots?

Yes. We women all have varying amounts of clots month to month, year to year. It's what you see vs what goes into the toilet, mostly. It's normal.
But maybe you should tell us what you mean by a lot... of course there are some unusual conditions.
There is also early miscarriage, which has a very tiny embryo you probably wouldn't see, but a lot of tissue built up even in a few weeks.

I wouldn't advise tampons, material should be allowed to pass in a natural way. You should be able to keep an eye on what is going on; tampons have been known to cause toxic shock syndrome.

tickle? Millions of women use them safely and don't keep an eye on what is coming out vs what clings to the tampon, clots or not. And she hasn't said what she means by a lot.