Thanks for the query.
You better consult gynecologist and go for:
Physical examination: to rule out any post-coital tear or cervical polyp
or erosion etc. which can cause bleeding during coitus.
for pregnancy: which will rule out the possibility of pregnancy.
Ultrasound: to find out the cause for your delayed periods or to rule out any other abnormality.
If needed the doctor may suggest hormonal
If everything is normal you can plan pregnancy in the next cycle by planning unprotected intercourse
around the time of ovulation.