Talk to Gynecologist on Trying To Conceive

Weight:46kgs. Married since 8 months.. Trying to conceive (cycle length varies from 28 days to 35 or 38 days) and every time before periods I felt many pregnancy like symptoms like sometimes nausea some times vertigo sometimes continuous pressure on bladder but periods came.. My last period came on 3 December and cycle length is 7 days. I m taking folic acid 5mg from few I want to take supplement which is specifically for conception.. I have listened alot about pregnacare Can I take it, if yes then for how many days should I take it and when to start the course.. Or recommend any other if more effective