Worrisome hcg levels

What hCG levels are rising properly. but after today's tests are not of the levels they should be at. The doctor said he likes to see them at a thousand and I'm a little over the 750.
I'm worried sick, been 6 long years and <a href="https://glowing.com/glow-fertility-program">ivf</a>. I just pray everything is ok. Anyone else had a similar but positive experience? They are rising just not as they should. They went from near tripling to a slow increase. So so worried!!