K since you started spotting at 10dpo that is a indication that you possibley have low progesterone issues. Any time you see bleeding even if it is just spotting before 12dpo that should be checked out by a 7dpo progesterone test. Not a cd 21 test since you ovulate way earlier than that it needs to be at 7dpo or as close as possible to that. 6-8 is acceptable. So talk to your dr and tell them you will call to schedual blood work for progesterone when your chart shows you ovulated and you calculate the date to go in.
I know it is frustrating and you may not have a progesterone problem but it needs to be checked so that you know for sure. Since low progesterone = very hard to stay pg. Since the egg dosnt have proper time to implant.