Hi guys just thought I'd pop in my two cents worth. Im a med student and have been looking in this issue.
Home preganancy tests test for human chorionic gonadotropin, which is a hormone that is produced by the planta tissue. It acts to maintain the corpus luteum (endometrial lining), providing a means for growth and maintenance of the pregnancy. HCG is present ONLY in women who are pregnant/have been pregnant recenctly. Implanon however released a constant low dose of etonogestrel, which is a type of progestin). Progestins and HCG have absolutely no chemical interaction, and as such, home pregnancy test can be trusted (as much as home pregancy tests can be).
Also, symptoms of bloating, mild cramping, spotting, amenorrhea (no period), headaches, and pretty much everything being described can be eplained away by the effects of progestin. So before you start to stress I would
a) consider whether these symptoms are happening in the first 3-6 months, as this is the period (no pun intended haha) in which symptoms are more intense.
b) take a home pregnancy test - THEY WILL WORK! (As long as you are far enough into the pregnancy, as HCG rises exponentially with the progression in pregnancy)
c) If you think it may be too early for a home pregnancy test, get a blood test. They are able to decet minute traces of HCG and you will find out a whole heap earlier.
Also, just wanted to say I too am experiencing the symptoms many of you are describing and I have been on implanon for 9 months, so I am booked into the doctor's tomorrow for a check-up :)
Finally, I just wasted to note that many doctors have practiced during a time period where Implanon was considered the Holy Grail of contraception, but there have been recent (within the last year) developments showing that it CAN be faulty and lead to pregnancy -
www.guardian.co.uk/lifeandstyle/2011/jan/09/implanon-implant-unwanted-pregnancy
www.bbc.co.uk/news/health-12117299
Thanks guys! Hope this helps! :o