Boyfriend and previous sexual partners

Hi ladies, I was wondering if is it normal to feel nervous if your current boyfriend/girlfriend/SO has had previous sexual partners? I’m a virgin and my boyfriend isn’t, I’ve never done anything sexual before, I’ve only kissed someone once. I don’t mind that his done it with others, I think I’m just nervous and keep thinking of silly thoughts such as, “What happens if he thinks his ex’s are better?” “What happens if I can’t pleasure him?” All these things, it’s making me so anxious and embarrassed to do anything with him. I’ve talked to him about it and his reassured me that he will enjoy it, but I don’t know..Is this normal thoughts? Is there any advice to maybe change these thoughts and feelings? Please let me know 💕