Hi!
To my knowledge, there is not anything reliable that would function in that way. IF the clomid is working, your own body should produce an LH surge that triggers ovulation.
I would be concerned that any "natural" fertility products, especially if they contain estrogen or progesterone might actually be COUNTER PRODUCTIVE.
You should be able to tell if you are ovulating in response to the clomid by the regularity of your cycles. If you are taking your clomid on cycle days 3-7, and the clomid is resulting in ovulation, your OPKs should be positive on cycle day 11-12, with ovulation on days 13-14 and a period on day 28-29. If you are not on a pretty tight schedule, the clomid is probably not working.
Another way to detect ovulation is with a progesterone level--these are fairly inexpensive and are best done on day 21 of the cycle.
Be very careful with the clomid--it really is best used under supervision--because it can produce large ovarian cysts that can cause problems for you.
Good luck!
Dr B
I personally found this website to be very helpful. It gives you different natural fertility options and in detail describes how to reach fertility with or without medications. Hope this helps. http://www.epigee.org/guide/infert.html