Is it normal to feel this way about love?

Right, so being in love with someone is probably the most beautiful and pure thing a person can experience.

However, after becoming "familiar", we'll say, with falling in love,is it normal to get feel this trepidation after the initial "hurray I love him/her!" feeling? It's sort of an "uh oh..been here before.." thing.

I get it now, and I'm a male. Is it normal to get this?

N.P. It's not that you stop being in love, it's this extra feeling of anxiety or caution. You could even say scared.