Is it normal to regret sex or am i being triggered by past sexual abuse?

im 17, when i was 5-7ish i was molested by a neighbor. me and this guy had sex last night. this was the first time i was intimate at all with him. up until this point we were good friends and it was nice. since i hooked up with him ive been having flashbacks doing it with him and i get a dirty feeling. i feel disgusted by myself. the guys very nice, the first guy ive actually liked his personality to and felt like he cared somewhat emotionally for me. i know it sounds bad. but is this a normal reaction or could it be myself being triggered by past abuse.