Just 3dpo...is it possible to have symptoms this early?

Question: I know there's probably a million questions like this already, but I really need some thoughts on my situation. I'm just 3dpo (running on a 27-day cycle for the past 3 months), and I've been cramping and my lower back has been really sore for the past 3-4 days. I've taken clomid for 6 cycles (this was my last cycle), along with hmg and hcg injections. I had a tvs done day 10, and it showed some free fluid in my cul-de-sac(my doc said it's probably an egg) and my dominant follicles were at the optimal level (>2cm in both ovaries). I can't even test right now to get an accurate result because of my hcg shot. Could get a blood test done, but then would have to get 2 done to c my hcg level rise for a real positive. Don't want to do that because where I live it's a bit costly and I don't want to end up regretting having wasted money on the test. Please help! Also, been having increasing amounts of cm(cervical mucus). I was diagnosed with pcos 8 months ago, but I'm normal weight for my stature and height (5'3" - 116lbs), not diabetic either. Just used to have really irregular periods until i started taking clomid 6 months ago.

Answer: I would think that since you had an hCG injection, it might mimic some pregnancy symptoms even if you're not pregnant (since it *is* the pregnancy hormone). It takes 5-10 days for a fertilized egg to implant, so typically you wouldn't feel any bona-fide symptoms until that point. Good luck to you!!