spotting

yesterday, i have some red pink mucus together with white mucus during pee. then i went to doc to check and scan for the first time. my lmp should be 7w6d but during scan the doc said measurement of the kantung was 5w and told me to come scan again next two weeks. does anyone having this situation? bcs kinda worried but abt that mucus doc said maybe only keputihan and ask me to monitor if happens again. is it normal having scan and size was not same as lmp? i read sometimes the ovulation is maybe late so fertilization is late than usual so not same as lmp but i need some experience from other people cz risau this is my first pregnancy after 1y married..