Movement at 13 weeks ?

Rebecca • Wife♡ My girls💕 + my angel👼🏼🌥 Grow through what you go through🦋🌿
Not to sure what I'm feeling. Exciting to think it could be my little lovebug😍 However, this is my first pregnancy so I'm not sure how high up baby is right now or anything ... It was my lower stomach and the best way I can describe it is it felt like a muscle spasm or something, but a lot of a pressure and almost like a swimming movement. Opinions?