Drug Use - All of the disorders producing stroke in toddlers and school-aged children may still produce stroke in adolescents. However, an increasing percentage of strokes, of both ischemic and hemorrhagic types, occur in relation to drug use. The most common drug causing stroke is cocaine in its smoked form (crack).
Implantation occurs 4-14 days after ovulation or sex. 4 is really early and not that common but it can happen. Implantation bleeding is brown (light or dark) or pink. The spotting lasts no more than 3 days, usually only about 1.
Implantation can start to occur as soon as 6-10 days after retrieval (I use after retrieval because embryos can be transferred on different days of development. Count the retrieval day as day 0). Five days after the retrieval a healthy embryo will have reached the blastocyst stage.