Thanks for your query.
I will try my best to provide you with best possible professional recommendations to your questions.
test kit is about 98% accurate and accuracy increases when the test is done with early morning sample.
Chances of pregnancy is very slim i advice you to go for scan that will help you.
Regarding the rectal bleeding
it should be evaluated as you are saying it is painful i think it is anal fissure
An anal fissure is caused by constipation
or a forceful bowel movement, though a tight anal muscle also may be a contributing factor. Once the skin is torn, each subsequent bowel movement can be painful, and the pain often is severe. The amount of bleeding that occurs with an anal fissure is small and usually is noticed in the toilet bowl or on the toilet paper as bright red in color.
Most fissures heal on their own and do not require treatment. However, some fissures may require treatment they include Cleansing more gently,
Diet changes -- eating more bulk, substances that absorb water while in the intestinal tract, Muscle relaxants applied to the skin, Numbing cream, if pain interferes with normal bowel movement, Petroleum jelly applied to the area, Sitz bath, Stool softeners.
All the above mentioned treatment options are useful for you
I advice you to meet surgeon for examination for your rectal bleeding.
I think missed period may be due to rectal bleeding which might have resulted in anemia
, which can cause menstrual irregularities.
Menstrual irregularity as side effect has not been mentioned with the use of lamotrigine
Yet again, I do hope that you have found something helpful and I will be glad to answer any further query.