I was just wondering has any one else ever experienced dropping a clot of blood in the toilet after having sex during pregnancy? And if so did you find out that this was normal ?

How far along are you? If you are early on in your pregnancy, you need to contact your OB/GYN to check for a miscarriage. If you are in your later trimesters you need to report this to your OB/GYN so that he/she can assess you for a possible placenta previa.