Letrozole and HCG trigger shot

Hi I am doing letrozole on day 3-7 with a trigger shot once I have a good follicle. This is month two and was given the go ahead for the HCG trigger shot this past Saturday after my ultrasound showed a good follicle last Friday. We did the deed a few times since and today I started spotting and have cramps. I’m on day 15. Has anyone else experienced this while doing this type of therapy? Was super excited and optimistic about a good follicle and now I have some anxiety. Any feedback would be awesome. Thanks :)