My pelvis is making a straight line 😳

So, something weird is happening.

Since the day I start having sex I discovered a weird change in my abdomen. First it was getting a little "wide" I am pretty sure I am not pregnant because I am birth control I use the implant and we had protected sex. But when I lay down it seems like my pelvis is actually making a line or a shape but it is just going straight. Is it normal 😕?

I want to take a picture but I am still shy🙈 sorry if can't give you much detail