Conception does not cause an aching feeling. You can get an aching crampy pre-period type of feeling after implantation takes place around the time your next period would be due. If you are having pain, you are not overreacting.
Where are you having this aching and how long does it last after sex? Does it happen during sex as well? Every time? How long has this been happening? Do you know at what point you are in your cycle?
This will help me to answer your question. Thanks.
