Talk to Gynecologist on Bleeding After 18 Days Of Missed Periods

wife k last month periods delay hvy thy 7 8 din late start hvy. thn is month 7 ko date ani thi bt we tried for conceiving periods missed hogye. we wait for 5 days thn test kia ghr mn jo negative aya. phr hmny 7 din dbra test krvaya jo k dbra negative aya. pr periods missing he rhy. we did intercourse again sb normal rha no bleeding etc... but now missed period k 18th day hmny dbra intercourse kia intercourse k bd blood aya jo k shuru mn lga k bht dark h maybe black. bt bd mn dark red ya normal red lga. wife says k usy yh periods nh lg rhy cz she didn't feel like usual. spotting ho rhi hai r viginal pain b. iski kya reason ho skti h