Strong Cramps After Protected Sex
For a pregnancy to occur a single lucky sperm is sufficient. Condom when used properly gives good protection against pregnancy and other Sexual diseases most of the time.
But in your case as you said the condom was taken off during the act there are many chances of getting pregnant. Because even before actual ejaculation due to excitation the male organ releases pre cum which may contains sperms. So even a single act of unprotected intercourse can lead to pregnancy.
The cramping that you had may or may not be due to pregnancy.Because in just 24 hours it is difficult to diagnose pregnancy.You will have wait till the you miss a period for diagnosis of pregnancy.
Alternatively you can take emergency contraceptive pill. Please take your doctors guidance for the same. You have to take it within 72 hours of act and sooner is better result. So take action if you want to avoid pregnancy which can happen in your case. But by and large unprotected relation can lead to pregnancy.
So take care and act accordingly, still there is something more to ask please go ahead and write to me. I am glad to answer them.