Is your uterus shrinking significantly during intercourse? I decided t…

Is your uterus shrinking significantly during intercourse? I decided to masturbate (only clitoris) because my doctor prescribed sexual abstinence until 12 weeks. And I immediately experienced all the pleasures of life, everything that could be reduced, up to pregnancy stimulation, the clitoris was only reduced in that area or not as brightly. In general, after uterine contractions, the lower abdomen tightened. So, will this be like this throughout the entire pregnancy? It's scary to suddenly have a miscarriage or other consequences... Or is this normal?