weird odor ... someone help me come to a conclusion

Okay so lately , my vag has had a weird odor and even after I showered and cleaned down there I can still smell the bad odor even if it wasn't strong. After sex it's strong. I've been having sex on my period maybe it's that? But idk. Cause I'll have sex and it's fine then in a little bit we'll go another round and then that's when the odor is stronger . I felt so embarrassed when he said something about it .